Depending on your integration requirements a pre-built module using the CC1101 chip is available that takes care of the more complex handshaking and coding issues. This is known as the rf1100-232, and a few google searches will find where is obtain it (like ebay).
All you have to do is send TTL level RS232 to the module and it does the rest. Receive decoding is done the same way. This module also has a sleep mode.
An example is shown here:
http://www.yesyes.info/index.php/electronics/rf1100-232-rf-433mhz-transceiver-module/If this is useful not too physically large for your project it may save a lot of work.