[JRTJH]

If what you're wanting to operate on the inverter is, as you say, "tv, dish, computer. Maybe a fan." then you can do that very easily with a 300 watt "point of use" inverter. You'll need to run two "heavy gauge wires (I'd say 8 ga stranded cables) from the battery to the point of use. Connect them to the inverter and plug the TV/DISH into the two inverter outlets. If you want to use the fan or the computer, then unplug something to plug in something else.

An LED TV consumes about 80 watts,
A laptop consumes about 120 watts,
A DISH receiver/satellite consumes about 200 watts
A small 10" box fan consumes about 40 watts

So, your inverter would have 2 outlets and you can "pick and choose" between the 4 items above, 2 outlets, 2 items..... Easy LOL

Now, as for batteries, you'll need "AT LEAST" a pair of 6 volt GC2 golf cart batteries. That 100 watt solar system will, on a bright sunny day, replenish about 1/2 of what you use each night. On a cloudy day or if camped under trees, etc, even less replenishment. We carry a 2000 watt Champion generator with us when we "boondock" I've found that in northern Michigan, the sunshine is not as dependable as "regular unleaded".... with the generator and enough gas, we don't need to rely on the sun....