Know your potential audience The most important thing about your website is knowing who it's targeting. Without knowing the potential audience you won't be very successful. Be sure to research sites that may be similar to what you're planning, it may be best to try to target a specific area rather than trying to do it all.
Security is an essential thing you should be researching when building a website. You don't want hackers messing with your business so it's always best to be clued up. Your business' details should be private, and to keep dodgy people from seeing it you'll want to have SSL Certificates. SSL Certificates are small data files that digitally bind a cryptographic key to an organisation's details. When these are installed on your site's web server it activates a virtual padlock and the https protocol which allows a secure connection from a web server to a browser.
You can buy and even test drive an SSL Certificate from a company such as Thawte. But why choose Thawte over another SSL provider? Well not only do they have 19 years of SSL experience, they also offer the most warrant and are one of a few SSL certificate providers which only focus on SSL as a core product. This means everything they do is pushed into making sure they do it best. You can take advantage of a 21 day SSL test trial so you can see just how important they are.
I've seen so many new sites fail at this, and it should one of the first things you nail. Before even looking at a design you should determine who will be writing the copy - it has to be someone with good grammar and spelling skills because a lack of those will look unprofessional and put off potential visitors/customers. It's also best not to be too smart with language, while you shouldn't dumb it down you should use words that almost everyone will understand, being too complex can put people off to.
You need to make sure you have the budget or a way to make enough to cover costs. If you're site traffic starts growing at a rapid speed you need to make sure that you can keep it going if you want to succeed. A dedicated server for your website is always good for future proofing.
Search engine optimisation
Search engine optimization is the process of affecting the visibility of a website in a search engine's natural search results. The more valuable content you create and creating partnerships with others who link to your site will help increase it's rank. SEO can be complex so it's best to do research on the subject so you know how to get the best traffic you can, you can even hire people to do it for you.
Obviously this is far from everything you should be considering when building a website, but these are the things you should never miss. Other things you may want to think about are design, ways to generate profit, and data collection.