Well, I think you have to be honest, first with yourself and then with any potential partner. If sex is an important part of a relationship for you, as it is for most people, then it deserves discussion in the same manner you would discuss any other elements of a relationship you are pursuing. For some reason, people find it awkward to talk about sex early on, but this is where a lot of potential problems could be headed off at the pass, if these conversations were made part of the fabric of a relationship early on.
A good way to bring it up in a newer relationship is to speak in terms of generalities, ie what you like sexually, rather than what you expect to DO with that person. Sometimes, sharing the little "things that turn you on" can be an intimate moment even if it doesn't immediately lead to sex right then and there. It will also let you know if the two of you are on the same page in your likes, or dramatically different. If your mate is completely creeped out even by the discussion, you'll have a good indicator of how communicative they'll be in the relationship- ugh.