it depends on what you are looking for...
shonen if you don't want the adult content...not necessarily x-rated but gore/language/etc
seinen if you want more adult complex storylines/situations....just take a peek at the top headings and read a few bios on the featured mangas
i recommend Berserk for seinen and Fullmetal Alchemist for shonen...but there are so many others
happy hunting and see around the forum....check this place out
Welcome to MH! (Your name sounds like Macaroni XD)
I do think that Manga is all about fun whenever you read, and also if you read you also learn something
Just try to read some mangas, and I agree with gnut that it depends on what genre that you're looking for.
Happy reading !