After the many uses of blankets, they all need to be cleaned often for a baby. They should be cleaned after being on the floor or even outside on the grass. If the blanket has only been on baby and on the baby's bedding, it should only need to be cleaned about once a week. The best way to clean baby blankets is in the wash with other baby items. Baby items should never be washed with a regular wash load. You should use a special detergent that is specially made for baby. Not using proper detergents and softeners can irritate the baby's skin, since regular detergents have harsh chemicals and dyes.
If you have one small stain that you want to pay attention to right away. One way is club soda, baking soda and vinegar. Applying any of those household items will clear the stain up right away with some warm water. You could even possibly use oxy clean or stain removers, preferably ones that are made for baby.
Once clean, you should hang the blanket to dry, or tumble dry on a low setting. Doing otherwise can make the blanket lose its shape and possibly shrink.