+1 to all of the above (including to avoid Armor All or any other "protectant")
Saddle soap is always a safe bet on smooth leather. It is a good idea to follow up the cleaning with a leather conditioner. Leather is/was skin, and giving it the same kind of care that you give your face (OK, let's say "that your wife gives her face") will keep it from drying out and cracking.
Griot's has leather-specific cleaners and conditioners. Mother's brand VLR (Vinyl-Leather-Rubber) is a one-step cleaner/treatment that can be used on just about any non-cloth upholstery. On old leather, I go all the way with Mother's leather cleaner followed by Mother's leather treatment. I've also use Bick's 4, which is sold at western stores as a cleaner/treatment for exotic skin boots.
I've been told in no uncertain terms that I should be using Connoly's Hide Food on the leather in the Bentley but I have too much Mother's, Bick's, etc to justify buying any more right now.