You should at least be able to remember where your tools, equipment and parts are when building a server of any sort. Generally, once you have that down, we assume that you remember the basics like your name and address, etc.
Sorry, I couldn't help it before You were being so vague.
Now that you have given a little more info we should be able to help a bit more.
Linux, in general, will use less system resources than it's Windows counterpart. For a light use webserver, 512MB will be plenty. As your website grows in popularity, you can start looking into upgrading your RAM.