Oh, also, the dial thermometers and hygrometers you buy in pet stores are not reliably accurate. Digital ones (such as anything by AcuRite, I've heard) work much better and only cost a few bucks more. Here's an example that costs $12 on Amazon. You will also need an infrared heat gun like this one, as well, because thermometers only measure ambient temperatures. Heat guns measure the temperature of a surface, so they're almost the only type of temperature measurement that works with under-tank heating mats, heat tape, and/or radiated heat panels.
You also will want to buy a thermostat marketed for use with reptiles. Heating mats etc do not measure their own temperature and WILL either not heat enough or burn your animal. The reason for specifically buying one marketed for use with reptiles is that other popular brands, like this one, do NOT have the failsafe function that reptile thermostats do.