I was wondering how you can make elites or any other biped hold any kind of weapon, like human weapon. I would also want to know how you can make them enter any type of vehicle like the warthog etc.

You're going to need ones that are modified to use cyborg hand nodes, or if you're going to play as one, there is a multiplayer elite here <

you can do so by making new model animations for a biped, or you can use the cmt animations assuming the elite is rigged to stock bones

just google search cmt elite animations

cmt's elite/hunter animations are a great choice. they're like reach versions.

Or just change the (forgotten name) thingo. Make a copy of the assault rifle, or whatever weapon, and change the "ar" or "sg" to "pr". The elite would hold it with one hand, but still works.

http://www.youtube.com/watch?v=tHqWv5xJOCI

Or just do this.