Most of the maintenance items on your trailer are components purchased from other manufacturers, like Atwood, Dometic, Lippert, Suburban, WFCO, etc. You should be able to download the operation manual and sometimes the installation manuals directly from their websites if you know which models you have.
For routine stuff here's a pretty helpful website:
http://rvbasics.com/
And of course post your questions here. Lots of folks with lots of experience willing to help!
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