DO yourself a favor and gather some information. Flea markets are littered with useless, inverters that people thought were bargains. Read: RV Power Inverter Comparison Tips

DO read the instructions carefully, more than once, and highlight the critical steps before attempting to connect an inverter. Some have elaborate instructions (good), but critical safety precautions are buried in the text and easily overlooked.

DO locate the power inverter as close to the batteries as possible. Use as heavy a cable as possible (read the instructions).

DO ventilate the power inverter well. They can get very warm. They need fresh air, just like a stereo or computer. Inverters do well in outside RV compartments as long as they are protected from the elements.

DO consider a small power inverter if it suites you need. Unless your wiring is inadequate, you can plug small inverters into standard 12VDC receptacles. This avoids installation issues and save money.

DO consider load transfer switches for larger power inverters even though they may cost more. if you also have a generator, make sure the transfer switch will handle three sources of power. Commercial power, generator power and inverter power.

DO make sure you know what you're doing when wiring an RV power inverter or get help from someone who does. Even if you use a professional electrician, make sure he understands that neutral and ground wires in an RV are NOT bonded together.

DO consider a power inverter a for your RV a priority item if medical appliances keep you tied to commercial power. (You can even plug the small ones into wheel chair batteries in many cases.)

DO buy a power inverter from a dealer who can advise you before you purchase.

DO buy a power inverter from a company that will let you return it for full (or nearly full) credit if it's in like new condition, original box, etc. Some inverters will cause radio/TV interference. Some will cause interference only on certain brands or models within brands. Good dealers will allow you to bring your RV to their place of business so inverters can be temporarily connected to test interference problems.

DON'T be afraid of RV power inverters. They're perfectly safe if used properly. They're not difficult to install if you follow the instructions. They can just about pay for themselves depending on what you use them for.

DON'T ever attempt to connect the power inverter to your electrical system with a simple jumper cord using a male connector (plug) at each end. The chance of shock or shorting the power invert is too great. And you will damage the inverter.

DON'T put the power inverter in the same compartment with the batteries unless you enclose it in its own, vented to the outside, "mini" compartment. Even if you're fortunate enough not to have a spark cause a battery explosion in a poorly located inverter, battery gases in the air will literally "eat" the insides of the inverter.

You may also want to read:
Choose the RV Power Inverter That Right For You
RV Power inverters - The Basics