My friend runs a motion capture company here in seattle. Here's his website:
http://www.mocapnow.com/
They offer motion capture services for companies large and small. Usually, you'd rent their studio for a day or two, bring in an actor, they'd help you setup the trackers and run their system, and then you'd capture motion data. After you capture the motion data, you may have to do some data cleanup. Generally speaking, what you're trying to do is map an actors bone structure to your animation bone structure and replay the actors bone rotations on the animation bone rotations. It's important to note that you only want to capture bone rotations, not bone positions (because bones don't stretch!).

You have two options: You can try to setup your own mocap hardware/software or you can rent out a studio for a day or two. If you look at the costs between the two options, renting the mocap studio is generally far more economical. If you setup your own mocap studio, you are going to be purchasing hardware, space, and spending time to setup and get proficient with the technology. Not only does it cost money, it also costs you a lot of time (and time is money!), and you don't have seasoned experts to help. I would only setup an internal mocap studio ONLY if I have a ton of mocap to do on a frequent basis (ie, large company with heavy production). If you're just an indie or a hobbyist, rent it out. Obviously, you want to plan out your shot list before renting studio time...

https://vimeo.com/blog/post/making-a-shot-list