While you can use products like Murphy's oil soap to clean any actual dirt or marks (on either suede or leather), we find wiping well with a wet rough cloth works great. If you do have suede rather than a polished leather, you can use a rough brush (like a fingernail brush) to dislodge any dirt and debris before using a wet cloth or cloth and oil soap - don't be afraid to get them wet cleaning them... they will dry and get supple again with wearing.
Next, we recommend using a matching shoe polish (or renovating cream) to touch up any actual damage areas. **This step is for smooth or polished hides only... there isn't an equivalent step with suede.
Once you have touched up and polished them, go over them with a weather protectant rub... our favourite being a mink oil and silicone blend. This both conditions and protects the leather. If you're using a spray (as suede owners would), this would be a good time to give them a spray before putting them away.
Some of our favourite products are: Woods Nano Water-proofing and Stain Repellant Spray, Cherry Blossom Renovating Cream and CAPO Arctic Dubbin Leather Waterproofing Compound with Silicone and Mink Oil which may be found online or at local footwear retailers.