The gas boat is a Prather Fun cruiser. A great starter boat. Looks to be in reasonable condition - in good shape they will sell for up to $500 used
The large sail boat. I cannot recall the manufacturer. I have been after one myself. Watched a few selling for around $200 for hull and old electronics inside in average condition. I would think up to $200 if no mast and sails are on hand. If complete certainly more $$
The smaller sail boat. Tough to say about size or condition. Again for Hull and basic electronics inside I would say in the $200 range - maybe more for a motivated buyer.
Boxes of electronics and remote controls. I imagine the controls should go to the models shown. Will add value if you can match the radio to the model. The other electronic items I cannot really say. Not a whole lot of value best I can see but again with some good pictures you may get a bit of interest - or just as a package deal.
I am no expert on the sail boats or electronics but I would say you have $1000 to $1300 worth of gear in the pics I could see (sail boats may be worth considerably more if mast and sails are on hand and in good shape). I would think the best way to sell would be to list the three boats (with radios if available) individually - a package deal of everything there will only serve to lower the price as most buyers will want either the gas boat or sail boats - not so much both.
Good pictures can certainly help with the sale. If the boats are in great shape (hard to tell) then take them outside and take some good pics to show them off. Will certainly benefit.
This site does have a free classified section - though realistically the biggest issue with the boats you have is going to be shipping. So perhaps craigslist or ebay selling as pick up only may save a lot of work packaging.