Usa visa question

I need a little help ive never been to america and ive seen all these different visa's i live in london and my girlfriend is all the way out in america, i wish to spend time with her, well a lenghy kind of time, i know i saw something about 90 days but i don't know what it is what is the longest time i could spent in the usa with her, she's at school and its primarly to go their and just be a tourist and stay with her with no work intended. i need help on what i should do and its hopefully planned to go see her next year sometime. somebody please help!

For the most part, a resident of an outside nation who wishes to visit the United States must first acquire a nonimmigrant visa for impermanent sit tight. The visa permits an outside national, to go to the United States port-of section and ask for consent of the U.S. migration reviewer to enter the U.S.

The "guest" visa is a nonimmigrant visa for persons wanting to enter the United States incidentally for business - B-1, for joy or therapeutic medicine (B-2), or mix of both (B-1/b-2) reasons.

So you should Apply for the B-2 Tourist Visitor Visa...