Welcome to the forums. Reading is your friend.
As a new RV owner, I usually recommend these articles that explain the electric systems in easy terms and also the SWDE Suburban water heater (if equipped)
You can just peruse them at your leisure. It may seem like sensory overload to begin with, but it's a lot easier than you may think.
First off, I would suggest just printing this following link off and putting it in your RV. It explains how your 30 amp RV is ALWAYS 120 volts. Many campers/electricians see that big 30 amp plug and incorrectly think it's 240 volts. If you ever connect to a 240 volt outlet (or have one wired that way at your home), you'll burn up your RV. It's always 120 volts.
http://www.myrv.us/Imgs/PDF/30-amp%20Service.pdf
Now that you understand you never connect to anything but a 120 volt outlet, these will make more sense.
Basic RV Electricity - RV Information (RV Maintenance)
RV Converters and Amp Draw - RV Information (RV Maintenance)
RV Electric
http://www.forestriverforums.com/for...tml#post327988
Also not knowing if the previous owner has the trailer winterized or not, you may need to be aware of the plumbing winterization valves. This is usually one of the main springtime problems we hear in the forums and why we keep it as a sticky at the top of the plumbing forums:
http://www.forestriverforums.com/for...st-103381.html