Download this ..
http://www.cockos.com/reaper/usergui...Guide1_83x.pdf
You may also want the sample projects from here ..
http://www.cockos.com/wiki/index.php..._Documentation (and look at the rest of the Wiki while there - hint: check the external links!)
There are also some videos here [urlhttp://www.reaper.fm/~pipeline/REAPERVideos/basics/[/url]