Identify your market. What kinds of people would each of your website ideas serve? Some websites, like Yahoo or Google, are as general as it gets, while other sites, like ILoveAlpacas.com, serve a very specific bunch. Write down the target market next to each of the ideas on your list. Conduct market research--Who is your audience? What do they do? How old are they? What are their other interests? All of this information can help you make your website more useful to you.
Do keyword research to determine if other people are searching for your topics and learn more about your potential clients. There are many free keyword tools to help you get more information about your topic. You will need to find keywords that are in demand (people are looking for it) yet have some chance of finding your site. Like a site on web hosting is too broad of a topic. Forum webhosting is a little better (narrower) topic.
Figure out your commitment. How much time and money are you willing to put into your website? You can start and run a website for free, but the more money you want to make from your site, the more time and money you'll have to invest. If you don't care too much about making money (like if you're just interested in showing off your dried bug collection) you can get away with free web hosting and sporadic maintenance.
Content sites will require less investment, but you will also face more competition, since anyone can start a content site. To make money from this kind of site, you provide information and generate income from the traffic you receive through advertising. The trick also will be to 'spin' your content and use specific keywords to narrow down your topic and write high quality content directed to specific people searching for those specific keywords.
E-commerce sites, which sell products, will need more maintenance and attention. You will also need to think about shipping, sales, order form security, inventory updates, and everything that a person with an offline storefront would have to manage.
You can also sell other people's products which will let you make money without investing in any products or worrying about shipping.
Narrow down your list. Which ideas stand to make the most profits? Which ideas require the most commitment? Which ideas look like they'd be fun to pursue? You will be spending time working on your website, so choose the idea you are most passionate about (that is also profitable and practical for you).
Register a domain name (one that's easy to remember and spell) and choose a web host. The best domain name also includes your main keywords and some variation of what solution you provide. For more complicated websites, be willing to shell out the extra bucks; or, you can opt for a free web hosting, which will probably mean having a URL like www.yourdomain.webhostname.com and have ads all over your website. Read the fine print.
Build your website. Here you have a few different options.
Get a website-building program and do it yourself. While this might work for your dried bug page, if you are unsure of your design eye and ability, then it's probably not the best choice if you're trying to make a sharp, professional impression (especially if you're trying to get people to part with their money).
Learn a programming language (or two, or three) and build a website from scratch.
HTML is incredibly easy to learn, and if you're up to it, you'll be able to tweak your web design any way you want, and you won't have to pay anybody else to update or change your site.
XHTML is the new web language set by W3C's standards. Almost identical to HTML, it follows a stricter set of rules for marking up information - what this means, for the most part, is minor changes to the way you write code.
CSS, which stands for "Cascading Style Sheets", gives more flexibility for styling the HTML.
Hire a professional. This is the best option for more advanced sites, especially e-commerce sites.
Use keywords that your target audience would search for to get a better search engine ranking. There are several tools available from Google, Overture, and third party software developers that can make the keyword research process easier. Sprinkle the keywords you've chosen throughout your text, but not to the extent that it hurts the quality of your content. Creating pages that are optimized for the search engines will help you get your site found which is really more important than design. What good is a site that no one sees?
Upload your website. Your web host may have an FTP feature, or you can download your own FTP program like FileZilla. If you hired a professional to design the website, he or she may take care of this for you.
Test drive your website. When you finish your website, do usability testing. You can do this by simply asking a few friends or family members to use your website. Give them a specific task like "edit your profile" or "buy an alpaca sweater from the bargains page." Sit behind them and watch them navigate. Do not help them. You will likely find areas where you need to improve navigation or clarify some instructions.
Advertise. Submit your site to major search engines. Tell your friends. Use an e-mail address with your domain. Visit other websites that complement (not compete with) yours, and offer to exchange links. Post constructively on blogs and forums, and put your URL in your signature.
Use article marketing to get back links to your website which will also help your website get found by the search engines.
Provide quality content and service. This is what will ultimately make your website awesome. Be sensitive to feedback - take it seriously. Think about your target market: their needs, their frustrations, their circumstances, and seek to make their lives easier. Strive for a win-win situation for you and your visitors.
Begin with simple things, practice them and then advance, even if what you create is not very impressive at the time; don't attempt to rush through the tutorials in one. You need to understand them very well, so take your time and test things out. If you wonder whether or not something will work, don't suppress the urge, but find out.
If you intend to sell a product on your website, you'll need to be able to accept secure credit card payments. You can apply for a merchant account, which charges a per-transaction fee, or use a free payment service like PayPal.
Before beginning to read a tutorial, make sure it's the best of the best; you don't want to find half way through that the tutorial's flawed or putting you to sleep. You don't want to have to read the same content over again in a good tutorial, do you? So look into lots of search engine results before picking your tutorial!
Find popular websites, even if they don't have much to do with yours, and use them as models. What are they doing right? Incorporate what you learn from the big shots into your own website. Don't be a copycat, but don't re-invent the wheel.
If you hire a professional to code a complicated site, remember that programmers are not all graphic designers. The most eye-catching sites out there have been made by or with the input of someone involved in graphic design. Programmer also don't usually know much about search engine optimization and getting your website to the top of Google. Try to find someone who does know that or you can learn on your own too.
Never violate your visitors' trust. Respect their privacy. Spam, annoying pop-ups, and irrelevant ads will hurt your credibility. A clear privacy statement is one way to build your credibility. Provide a prominent link to your privacy statement from every page on the site as well as from any location that you are asking your visitors for personal information. Provide legitimate contact information online. If you need to use ads on your website, explain to your visitors why, and show them that you're doing your best to accommodate their visit. And mean it!
Remember, never delete the details (username, password, etc.) of your account. If you don't have the details when you forget them, you will not be able to work on your website again. More importantly, never give out your details (except for your website address).