I am having trouble with the idle starting very high no matter how warm the truck is when I start it. It always idles down after about 30 seconds

 

First things first, remove the IAC (idle air control valve) on the throttle body and clean it. It can stick and cause high idle problems at times. You can use regular throttle body cleaner to clean it, get it realllly good 'til the stuff draining out comes out clean, then let it air dry before replacing it.

Secondly, if that doesn't do the trick, clean the MAF and check for vacuum leaks, but I got my money on the IAC.