Both terms, suspensions and colloids, refer to specific types of mixtures. A mixture is a combination of two or more substances that are chemically combined. A supreme pizza (one that has a little of all the ingredients available) is a great example of a mixture. The substances that go into making up all the ingredients for the pizza are easily separated. If you don't like green peppers, pick them off!
A suspension is a special type of mixture that has particles suspended in solution that are too large to stay permanently suspended in the solution. Orange juice would be a great example of this. There is a reason why one "shakes up" the orange juice container before pouring a glass: to get all the particles of pulp and orange concentrate to mix back into the more aqueous part of the solution. If one allows the orange juice to "sit" too long, one will observe the separation of the large particles and the aqueous part.
A colloid is a special type of mixture which has particles, similar to the suspension, but the particles are much smaller. The particles are small enough, in fact, that they will remain in aqueous suspension indefinitely. A glass of milk is a perfect example of a colloidal mixture. The particles in the milk are small enough so as to remain in solution indefinitely.