If you can get to the stereo you know enough to replace the bulbs...don't waste your time reading up. Common sense will get it done. Pull out the climate control unit, open it up, replace the bulbs...it's really simple. Search for a stereo install write-up if you have not taken the dash apart before.
Spark plugs: http://4runners.org/
Climate control: http://www.yotatech.com/f2/digital-climate-control-burnt-out-fix-76598/
Search: http://toyota-4runner.org/search.php:yesyes: