Hi Dude,
The PCA website has alot of good info on leather seat care,
www.pca.org, I went with their cleaning tips with great results.
I first clean with the P21S car conditioning shampoo (mixed 1 capful with a bucket of water). This works great for the rest of the interior as well.
I then follow with the 2 Lexol leather products on the middle portion of the seat. I don't have the full leather seat package, so just the center part is made of leather with the sides and back being vinyl.
I finish this up with the Lexol vinyl protectant on the the sides and back of the seat.