Okay, first, some general info about the series:
Accel World is about a VR game called Brain Burst and the adventures of characters within the game. The series borrows many concepts from SAO, particularly the Alicization arc, so you'll find some things very familiar.
Accel World has the light novels as the source material and contains 25 volumes at the moment. It has not ended yet; the story is still going
The anime covers Volume 1 - 4 as well as two of the side stories from Volume 10.
Now for the questions:
Q: Where did season 1 left off in the light novel
A: Season 1 covered Volumes 1 - 4 and two of the side stories out of Volume 10, meaning that everything starting from Volume 5 is not covered in the anime.
Q: What did the OVA and Movie covers in the novel (and where did it left off)
A: I'm not sure when the OVAs occur exactly, but they're not too important anyways. As for the movie, it actually occurs a few days after Volume 25, which is currently the last book of the series (series still has not ended; the author's writing more). You should not watch the movie without reading some of the novels first.
Q: What is this sao x aw versus thingy and what does that crossover doing in one of the light novel volumes ( my friend told me to skip that volume so i just asking some experts opinions )
A: Accel World vs. Sword Art Online is a game that features a crossover between the two series. It's commonly regarded as non-canon in the gameverse and is definitely non-canon in the main AW series. As in the short crossover story titled "Versus" in Volume 10, it is just a non-canon side story that was done for fun.
Q: Is there anything that i need to skip / re read in the novels because my friend says that some part of the anime didn't adapt the light novel well
A: The anime was a pretty good adaptation of the light novels; almost everything in the light novels was covered in the anime. If you want to know more after watching the anime, you can jump straight to Volume 5 without rereading Volumes 1 - 4.
Q: Also my friend say something about the episode order that is a little bit messed up so whats that
A: The episode order of the anime isn't messed up; they're placed in chronological order. You can watch it as it is.
I hope that answers everything : )