Well first off im going to say that i want to get the trophy for pick pocketing 50 people but, when i pick pocket somebody sometimes it doesn't count. Whats the easiest way to complete this challenge ?

Is pick pocketing beneficial in New Vegas? Is it as in depth as Skyrim's pick pocketing?

I am unsure of your meaning by in depth, but it isn't as focused on if you are comparing it to Skyrim. I don't believe there to be any related perks or skills, but it is determined by your sneak skill.

Pick pocket sleeping people. I got it by pick pocketing dog tags off NCR troops.