I just use regular old Kiwi brand Saddle soap. Go by the directions and you can't go wrong. Usually Wal-Mart sells it for a decent price.
+1
Kiwi Saddle Soap is the safest stuff to use on any leather. It's very low Ph, contains an extremely mild conditioner, is simple to use and available just about everywhere. You can't really harm anything leather using it, which is not true of some of the leather "conditioning" products out there. The stuff's been around forever because it works and works well.
I like the fact that you can also use it on boots, seats, etc.
If you use it on a regular basis it really helps keep the leather supple and you shouldn't need any other products.
Stay away from stuff like Mink Oil and anything that has waterproofing qualities. They usually leave a residue that's a bitch to get off.