One Pieces have exploded on the scene in the past few seasons and He is a huge fan. Although they eliminate the "easy access" capabilities, the look of them makes it well worth it. (HE-ditor's note: they are not for everyone!)
There is the obvious choice and probably the most popular - American Apparel and American Apparel. But just because American Apparel is popular, does not mean you should make them your exclusive one piece provider. Lace and Sheer material typically make for the best looking one pieces.
What to wear it with and how to wear it: Good question. Black is always the preferred. They work great with a tight pair of jeans or a skirt (high waisted or not). This is not the time for trying to reinvent the wheel. He has seem some girls try to wear a bra underneath, and it was probably the dumbest thing going. Backless one pieces are definitely a sexy way to show off some skin.
Go out this weekend, rock your one piece, send He your pics and the person who wore it best, will win a He-prize.
-He
P.S. Needs more tips? He-mail fashionbyhe@gmail.com for help.