UPDATED DECEMBER 20, 2009: Link fixed.
Hope this doesn’t come across as self-promotion. I had heard of this page before but hadn’t looked at it because of the assumption that it was just more trannie-fetishising (as in, how to get the transboy of your dreams and keep him in a cage so you can show your friends how cool you are for dating a transboy). But I finally checked it out and it’s a very thorough list of things to consider for anyone to who is sexually or emotionally involved with an FTM. Worth checking out even if you’re not in that situation as some of the stuff applies even in non-sexual or non-emotional contexts.