Honestly, there are any number of books on this topic, just search amazon for 'dirty japanese' or 'japanese slang' or 'street japanese', etc, etc.
In any case, Japanese 'insults' and 'cussing' tend to sound extremely mild if translated literally and are only offensive if you are thoroughly versed in Japanese culture, with a handful of exceptions. Most of the straightforward derogatory terms are just childish insults, you have to be more subtle to be really cutting.
Explicit bedroom talk is another matter, and is pretty much the same as any other language with a range of terms in varying levels of bluntness, and 'adult' sounding versus 'childish' sounding terms for various body parts and acts that combine them.
In any case, pretty much everything is documented in the EDICT database (the japanese-english dictionary data maintained by wwwjdic.com, and used by most free japanese-english dictionary apps), so if you actually come across any of these terms they're easy enough to look up the meaning of. (They're actually included to a somewhat distracting degree; some phrases that are perfectly normal and common *can* have another meaning in the right context.)
The upshot of which is, if you're trying to understand explicit material, there's no problem with looking it up just like any other term you might look up in the dictionary. Takes away some of the taboo nature of such language, but such is life!
PS: Not a mod, just trying to point the OP in the right direction without exposing anyone to said rough language.