For people without space/money for a dedicated workshop, probably the best power tool to get
(after a decent cordless drill) would be a
Track Saw.
It is basically a Skilsaw on steriods, but way way more than that.
A woodworker friend of mine has built high-standard complete kitchen cabinetry with one, using the living room carpet as his workshop. Without creating much of a mess, either. The dust collection
(using a shopvac) on these is generally unbelievably good.
I have the Makita version, and both a 5' track and a 9' track. Absolutely excellent. But even the lowly ShopFox versions ought to be way better than the non-tracked alternatives.
We use an 8'x4' sheet of rigid foam
(insulation) as a work surface
(on the floor), placing the sheet goods on top of it so that the blade can be set to cut through the wood into the top 1/16" of the foam. Excellent straight, splinter-free cuts, with no big mess.
Cheers