If your F250 has the stock radio, there are no preamp outputs, so you will need to use the speaker outputs. The best solution would be to wire a LOC (line output converter) to the rear channels and run RCA cables to the amp.
Speaker wire color code:
Left rear positive - Gray/Light Blue
Left rear negative - Tan/Yellow
Right rear positive - Orange/Red
Right rear negative - Brown/Pink
You'll need an amp wiring kit with 4gauge power and ground. Both the LOC and wiring kits are available at numerous online stores. The best service is from www.crutchfield.com
. Another reputable online seller is www.sonicelectronix.com
You did not say what subwoofer(s) you intend to use with the amp. If you want to stick with the Maxxsonics product, a pair of 10" Orion HP10D2's would be an excellent match. Wire each of the subs dual voice coils in series for 4ohms, then parallel them to the amp for a final load of 2ohms. Both of the linked retailers above sell the Orion's and many other brands as well. Just make sure that your sub selection has adequate power handling capability. At least 1000 watts RMS if you use a single sub and 500 watts RMS if you go with 2.
Hope this helps.