Hi, and welcome to GFY
It is not easy to "pick" a domain name, since most good domain names are already taken. But you should stick to something within the niche you choose, and same with basic keywords.
The best thing is to start your website, and then install a search script for your site which also tag what your surfers are looking for, in a tag cloud. That way you will have a dynamic page and more popular search queries. Google loves that.
I don't know what kind of site you have, or are going to launch, but with a blog the keywords come by themselves when you write it. But if it is a TGP or similar, you should also import the descriptions for the galleries, and attached them as titles with the thumbs. And then make archives (like a 2nd, 3rd page and so on..) to keep the words alive for longer.
If you are going to create galleries, you should use softwares to do it fast. Time is always the limit. And make keywords for those sub-url. If you choose to use search tag cloud for your website, also make sure the cloud is relevant for your website (query results > 0 hits), so your galleries are deep-linked.
General advise: Keep
everything organized from the beginning. That is something I learned... the hard way
PS. There are "certain" keywords you should not use. Not only because of the established ethics, but also because of sponsors and billing processors policy... and law. Always keep that in mind
