A GoPro is a great option. They capture great video and can be mounted nearly anywhere on the bike. I've never mounted the camera to my helmet, but many have with success. There are other options out there, but I have not used them. I have a GoPro Hero2 and a Hero3 Silver. Both are great.
Here are a few from my track day excursions from 2013.
Here is my 1st track day ever (April at VIR South)
June at VIR South
After a full track day makeover on the bike, here I am at NCBike in Sept.
I ran Bridgestone's Battlax S20 tires all last season on my GSXR 600. They worked great and stuck like glue. After about 1/2 a lap, the tires were ready to go. I run a low to medium intermediate pace, and they worked great for me. You might want to give them a try.
Here are a few videos from Saturday at NCBike. The last video is from a very wet session after lunch.
http://youtu.be/c_-D26m4ePc
http://youtu.be/n5x-eM3imiE
http://youtu.be/XGaHsoSO3SQ
I've been to the track once before (with a different organization). The gravel paddock area is not that bad--just bring a piece of plywood if you are planning on using stands and tire warmers. There were several spots open along the road when I last went, but I chose the gravel paddock...
I'm in for Saturday--wish I could stay the entire weekend, but can't. I ran NCBike with TPM a few weeks ago to get myself ready for the NESBA event.:D The track is a lot of fun, and it's a great place to work on your cornering skills!!
I'm hoping my rear tire will last through this one, last...
Here are a few more videos from Saturday (6/29)
Session #1--forward facing cam
http://youtu.be/Yhcxf2uCTbM
Session #2 after red flat--posted in above post
Session #3--forward facing cam
http://youtu.be/ZvpoCWWBl7M
Session #4--cam mounted on tail section aimed forward to check body position...