Bill, do you want to build a concrete base or foundation for the brick to sit on, or do you want the bricks to free float on a bed of sand?
One is alot cheaper and requires more maintenance and the other is pretty much maintenance free.
Also, instead of brick, I think you mean pavers, correct?
Decide first if you want the pavers even or flush with the lawn or a pavers height above the grass.
This plan is for pavers even with the grass or turf.
I would first make sure the area is void of any cables and lines.
Then I would mark out the area for the patio with line and markers. Get a can of marker spray and outline the lawn area you want to change to a patio.
Now, with a sharpshooter, dig down the depth of a paver, 6 inches for concrete foundations, and then 3 too 4 inches for sand and aggregate.
Make the cuttings nice and square and smooth. Now, if you have not had any rain, water in the area real well. This will compress the soil some.
Now add in your aggregate first then fill in with cheap sand up to 3 to 4 inches. Water in the sand and you want 3 to 4 inches of settled down sand.
Now add some rebar structures and pour in the concrete to 6 inches, while still wet, fit in your pavers on and slightly into the concrete. The surface of the concrete must be exactly level or a slight fall away from the home.
**Here you can do as the above and apply on the wet concrete or apply on the concrete when it is dry. I prefer the application on dry concrete.
After the pavers are set on the concrete, then apply mortar dry on the pavers and work the dry mix in between the cracks with a broom. When all worked down, then spray water the patio.
Now lay down your surrounding border to lock everything in place and you are now set.
On the sand base, you just sub sand for the concrete and ensuring that you water and tamp the sand down very tight. I would lay a weed barrier down before the sand is applied.