Perhaps surprisingly it is just as important to give your suede shoes a little tlc from time to time as it is for leather shoes. Suede is rather more delicate than leather and how you care for them does differ from the care of leather shoes. http://blog.loake.co.uk/how-to-care-for-suede/
In order to revive the nap and lose any surface dirt you should, ideally, brush your suede shoes after each outing. Suede brushes are often brass wire and are intended to raise the nap but unless used fairly gently can be a little too aggressive on the suede. Alternative composite suede brushes are available which have a mixture of materials to make up the brush and will have a gentler effect. Contrary to popular opinion you should not brush in a circular motion but brush in a single direction in order to avoid simply brushing the dirt around the shoe.
There are various spray protectors on the market and they do offer a sound method of protecting your suede shoes. You should spray evenly all around the shoe before that first outing. Some suede shoes do come impregnated with some form of protection when new but there is no way of really knowing this until it’s too late. Spray manufacturers will advise you to test the spray on a small area but I wonder just how realistic this is. I would advise that it’s better to risk a very slight change of shade to the risk of receiving a stubborn mark from that spilt drink. The shoes should be re-sprayed regularly to ensure the protection remains for the life of the shoes.
To remove mild stains gentle rubbing with a suede cleaning block can work wonders. Alternatively rubbing one shoe against the other can be surprisingly effective. Once the stain has successfully been removed brush and spray again.