Do not wash "air-type-sneakers" in a machine, you are likely to experience a blowout.
Stan Smith and similar tennis shoes handle washing machines pretty well.
How to take care of your sneakers.
You have to keep your shoes very neat and clean. This is a big problem for me since I'm not very good at keeping anything clean. To keep your shoes in mint condition you have to clean them every day. This is how you do it.
1. Mix water and washing-up liquid.
2. Soak shoes in water, but not too much, after all, it's leather we're dealing with here.
3. Scrub shoes with a toothbrush or nailbrush. An eraser works wonders with spots. Steel wool is also excellent stuff.
4. Let shoes dry on a steel hanger. If you stuff them with newspapers they won't loose their beautiful shape.
If you are desperate
Some spots are just too difficult. If you are faced with the choice between giving your shoes up and throwing them in the washing machine, it's worth a try unless they're suede shoes (fake suede is usually OK though). Sometimes your sneakers look like new. Sometimes they look dead. Then you have to bury them at the sneaker graveyard, because a sneaker freak would never throw away favourite sneakers. My graveyard is a big bag in the attic.