Here are a series of articles from Essex, a brake parts distributor for professional and amateur race cars.
1. How to Bed-in Brake Pads and Rotors
http://www.essexparts.com/learning-c...ds/post/Bed-in
In this article the author talks about why and how to bed-in new brake pads.
2. Swapping Between Street and Race Brake Pads
http://www.essexparts.com/learning-c.../swapping_pads
In short, Essex suggests that it may be a good idea to scrub off the original pad material of a different pad from the rotor before bedding in your new pads. This way, you can avoid vibration, judder, and uneven pad deposits.
I personally feel this is a bit excessive for the recreational track enthusiasts. But it is probably very important for those who push their brakes to the limit.
Good information to know nonetheless.
3. How to Choose the Best Street and Track Brake Pads
http://www.essexparts.com/learning-c...ose-brake-pads
There is rarely a one-size-fits-all brake pad. Here's why.