You can find the Acurite at Walmart in the house section.... Like the aisles with fans etc. should be a few options, you want the one with a probe. I discovered though that some Wally worlds do not carry it, you can check it by going to their website.

the clicking sound is the thermostat working. Clicks on and off as it maintains temps. You'll want to set it at about 88? I question this because of the paper towels for substrate. I've never used them so not certain but I suspect lower than what I set mine at which is 90 because I use about 1/2" of reptibark and Eco earth mixed as substrate.

Aaron was kind enough to provide a link for you, read it... These guys know their stuff. <I'll be heading there as soon as I finish boring you to tears.>