Yeah, I recommend Lexol. I've had good luck with it, as have many folks that I know. My favorite conditioner is Crema Nubiana (or Alpina), but apparently it's getting harder to find. Allen Edmonds makes a decent one as well.
Don't use saddle soap on nice dress shoes. Many people do, but it's bad for the leather in the long term.
My process: first brush the shoes with a horsehair brush. If necessary, wipe off any dirt/mud with a slightly damp (with water) towel, then dry them immediately. Hit each shoe with a leather conditioner and give it time to soak in. This amount of time usually depends on how often you condition them. For a first time use, I'd give at least an hour for the conditioner to absorb (some people wait overnight). If you condition/polish your shoes every week or so, you shouldn't need to wait more than 15 minutes. Then brush with a horsehair brush (if you have black shoes and brown shoes, you need a brush for each). Follow that with some polish, cream or wax, wait a few minutes for it to dry, brush, then buff with a soft cloth.
When you condition your shoes, make sure to hit the soles as well (if they are leather). It's also a good practice to polish the underside of your shoe in front of the heel (the part that doesn't touch the ground). This improves the overall appearance of the shoe, especially if you have your legs crossed and the underside can be seen.
As far as how often to polish your shoes...that's really up to you. I know many gentlemen who polish their shoes after every wear, condition them every couple of wears. After each wear I'll put the trees back in my shoes and give them a good brush. On the weekend I set a few minutes aside and give all the shoes that have been worn during the week a polish.
After some time it may be necessary to use edge dressing to correct color that has been lost from the welt--when you do this, be careful!!! Especially on any non-black shoes. Edge dressing can permanently stain leather that it comes into contact with.
IMO investing in some cedar shoe trees is imperative if you want your shoes to last. Cedar is used because it helps to suck up any moisture on the inside of the shoe and it's naturally anti-bacterial. Also, try not to wear your shoes on consecutive days so they have time to completely dry out between uses.
With minimal maintenance, well built dress shoes should last for decades.
