I use mostly everything Mothers, but Meguiar's has a good 3-step system from what I hear. Pep Boys I think carries both.
If you got a clay bar kit, I know the Mothers includes a pretty good Carnauba Cleaner Wax that certainly cleans better than any synthetic wax I've tried... it's also available in larger bottles or a quite nice paste. Other clay kits include a wax, but I haven't tried them. The Mothers Carnauba Cleaner Wax removes pretty big scuffs off my '93 cashmere beige Camry XLS by hand. On a neighbor's white F-150 I removed permanent marker that some kids drew on her fender. So I really like that as a one-step if you need some cleaning.
Whether you need a 3 Step or a good 1-Step on a white car is up to you and your eye (and the amount of time you have).
My Camry's got some neglect on the trim, and I use a lot of Back-to-Black when Protectant won't do the job... and I do detail all of the trim before waxing to prevent staining.
I do like Rain-X Original for the exterior glass, but I don't think you need to use a glass cleaner beforehand (except, of course, on the insides).
For dirty leather, I recommend a good vacuuming of the seams and then a two-step Cleaner and Conditioner -- spray the cleaner on an applicator to avoid staining.
I like the Mothers Carpet & Upholstery Cleaner for both the carpet and the vinyl on the dash (I'll spray it on a water-moistened cloth). Protectant works good to give it some richness.
Protectant works good on the tires as a dressing... if they're really dirty, I like my old standby, Bleche-White.
Use an All Wheel cleaner for wheels if you have serious brake dust build-up.
I do find the Detail Guide useful, and you may, too... just visit
www.detailguide.com.
Everything I mentioned above can be had at Pep Boys and the major auto stores.