I've looked at a couple of the previously posted threads on this but wanted to post my specific info.

It was running fine, then when I went to leave a friend's house it would not turnover. It clicks.

I HAVE POWER to everything - wipers, headlights radio, etc.

I have a 3rd party alarm system.

I will be calling the dealership and alarm installer and picking their brains.

No, I have not checked the fuses yet; I will be doing that tonight. My intent is to gather as much info as possible so that when I get back to the truck tonight I can just rattle off a series of solutions and hope one of them works and I drive home.

thx in advance.

Check your battery terminal connections. Sometimes even though they appear nice and tight, they may not have a good contact and it's getting enough juice to power lights and accessories but not the amperage to start it. Unhook the battery, clean the terminals and cables really good then try again.

If it's clicking, I doubt it's a fuse but wouldn't hurt to check.

x2 on what Drake said. I went to so far as to replace the battery only to find out that the termals connections had just worked loose on my previous battery. Luckily Napa returns batteries that are unused ;).