The most basic tools are: hobby knives (some folks use surgical scalpels instead), sanding sticks and/or files, and some way to apply glue / cement in very controlled ways. A few models may require a few drill bits and a pin vise. I think that almost everyone works on a self-healing cutting mat. That's pretty basic, and it will get you pretty far. There's also the matter of painting, which often includes an airbrush (with the absolutely mandatory cleaning kit), and some very fine (small) paint brushes. For photo etch, you need some different glue, possibly some different blades for the knives, and I prefer to use a folding tool. You will want a hard plastic surface to cut the PE, as the self-healing mat will cause PE to bend uncontrollably as you cut it. The different glue or glues may also imply some different applicators.
You can usually arrange for the turrets to turn by simply not gluing them to the deck - that's actually what the real ships did, although admittedly there was rather less chance of the real ship turning over and having them fall off!
In most cases you can easily arrange for a little plastic "inverted mushroom" that retains the turret but still allows it to rotate.
There are a variety of resources for figuring out which paint from which vendor is like that paint from another vendor. One of them is here:
http://www.paint4models.com/Photo etch varies widely. Some PE parts really need to go on pretty early, else you'll have a terrible time doing it later after other parts go around it. Some other parts (railings around the bow or quarter deck) really should be almost last as you'll destroy them trying to build other parts of the model. Some folks paint the PE before it goes on, others later, and again sometimes it depends on just which part you're considering.
Washing the model gets skin oil and other similar stuff (release compound) off of the surface before painting. Even if the paint sticks to the oil (most doesn't, or at least not very well), the oil definitely doesn't stick to the model permanently, so it's important to get it all off before painting or else you could end up with (say) a thumbprint - or more likely an overlapping batch of thumbprints - "etched" into the paint as the oil detaches and takes the paint with it. (Or the paint may never have stuck to begin with.) The air drying, of course, is to prevent getting MORE oil onto the model.
You might try David Griffith's
Ship Models from Kits. It goes over all of this (and a lot more, like rigging and water).