Tips on using Bricklink.

First make a wanted list by going here. You can put in the item and notes, price limit or quantity. Many shops will put the same item in many lots to inflate the lot count. So I don't recommend using the quantity as it will eliminate store incorrectly.

Finding the item you want is tricky. One way is to look at the inventory of a set and find it that way.

Next see what shops have the item you want by clicking here.

The catalog has a ton of data included: prices paid for new and used as well as prices and quantity that stores are offering.

Another place to shop is Lego's Pick a Brick.