Shoes are a size 1-3 for infants usually, 4-13 for toddlers/preschoolers, then the numbers start over for bigger kids from 1-5 and then you are in adult sizes.
Clothes start at infant levels (preemie, 0-3 months, etc up to 24 months) and then you move to toddler sizes (2T-4T/5T). 2T and 24 month sizes are basically the same. There might be slight differences in the room of the seat (allowing for diapers in a 24mo size) or in length (some 2Ts are slightly longer then their identical 24mo cousins). After that you move to kid sizes. Boys and girls sizing may be different. A girl's size 4 is usually the same as a 4T but cut slimmer and slightly longer, same with a 5.
Kids come in all sizes so it's best to just try stuff on. My 3yo is wearing 4 slims and 4/5 shirts (from the girls dept) which is the same size her older sister wore at 5 and 6 years old. My son wore 3Ts at 18 months and was in 4/5 size pants at 2 1/2.
at 9:30 AM on Oct. 7, 2009