I would like to install in-ceiling and some in-wall speakers in several rooms in my house. I would also like to have volume controls in each room as well. What are the basic components that I will need to get started.

Im not sure what your staring with so I will lay out the basic components of a simple in-ceiling/in-wall sound system with volume controls. First you will need a sound source. A stereo tuner is commonly used as a source for distributed audio. Other components such as a CD or DVD player or TV can be connected to the tuner. You should select a stereo tuner with 2 channels (right and left) for 2 speakers per room, rather that a surround sound tuner, unless you plan to have surround sound in every room which requires 5 or 7 speakers for each room. You will also need one volume control and 2 speakers per room, and wire to connect it all. You should use 16 gauge or 18 gauge speaker wire, with 2 conducters. Since you are installing speakers in several rooms, you will also need a simple distribution hub or connecting block to distribute the signal from the source. How many rooms are you doing?

Thanks for such a fast reply! Im have a stereo tuner I plan to use for the source. I plan on installing speakers in 5 rooms for now, and possibly 2 more later. I have some 8" round speakers picked out and volume controls, but I have no idea about a hub or connecting block. Im also not sure about the proper path for the wiring to the speakers and volume controls. Can you recommend a distribution hub or connecting block?

The NXG NX-VCH8 Volume Control Distribution Hub is a good example of a simple hub. This model usually costs around $50. It has one input terminal and 8 outputs.
Assuming you are using a 2 conductor cable, you will need 2 runs (one right and one left) from the source to the hub, then 2 runs from the hub to each volume control. You will also need 2 runs from each volume control to the speakers it will control. Be sure to label all your cabels "right" and "left" and pay very close attention to connect the + and - of each cable correctly. The source, the hub, the volume controls and the speakers will be labeled for right, left and + and - .