Ok,, Inverters come in (for this post) Two flavors.. Pass through and stand alone.
A pass through will have AC-IN as well as AC-OUT It also charges batteries
The Stand Alone has only 12 volt IN and 120 volt OUT.
here is the basic hookup.
First: Mount the inverter in a compartment NEAR the batteries but NOT in the same air space.. They must not breath the same air
Connect using heavy (Like 0000ga) wire,,One Red, One Black and for as much of the run as possible tape the wires side by dide.. Use a proper size "T" fuse in the positive line.. Likely 150 to 200 amps. (Download manual for device)
In the Main power (120 volt) Distribution panel mark the circuits you wish to move to the inverter.. Due to my past employment I call a 2nd distribution panel you will install the "E" panel (Emergency) but the proper name is SUB panel.. More on that later.
Replace one of the breakers you will move with a 20,25 or 30 amp breaker (As specified in the Inverter manual which you downloaded).
10 ga wire from that breaker to inverter A/C in and 10 ga back to the Sub Panel (This assumes no circuit breakers on the inverter)
Move E-Circuits to the sub panel (TV, Microwave, GFCI)
IF inverter has breakers you may extend the power lines direct to the breakers on the inverter... But this limits the number you can run.
Stand alone Method 1
12 volt as above.
120 volt from breakers on inverter to destination (IE TV/Electronics bay)
Install a RED or ORANGE outlet and when you want inverter power manually transfer load.
Install the proper size breaker in main powrer panel as in "PASS THROUGH" only do not (yet) run the lead to the inverter
Run a line from the inverter (12ga is OK here in fact 14ga is but I'd run 12) to a transfer switch (Manual or automatic)
Run a 10 ga from breaker in main panel to the other side of the transfer switch.. Switch feeds sub panel.
Manual switch.. label as to INVRTER and MAINS
Auto: Mains (The line from the circuit breaker) Goes to GENERATOR
Inverter line goes to MAIN (OR Shore).
Hopefull this covers it.
Home is where I park it!