Prepare the barbecue base
A brick barbecue is going to be heavy, so it will need a solid base. Some large pavers laid on a bed of sand might be an OK base, but if you really want to make your barbecue something special, you need to prepare a real base for it.
1. To create a solid base, dig down and remove the dirt from an area about 4 feet by 4 feet. Make the hole 4 inches deep, then install 6-inch wooden forms along the insides of the hole.
2. Use concrete mix cement that you just need to add water to and can mix in a wheelbarrow. Pour in about 3 inches of cement and then lay in three pieces of rebar 3 1/2 feet long and 12 inches from each other. Cover the rebar with another 3 inches of cement and smooth the base.
3. It's a good idea to build in a slight slope or grade to the base (say 1/2" from back to front) so rainwater will run off the foundation. Now just let the base set up for 48 hours.
While you are waiting for your cement to set up, go and buy your fire pan and barbecue grills, available at barbecue stores or even home centers. You'll need to have these before you begin building the barbecue so you can be sure they will fit.