Can I get a rundown of the whole frigate/cruiser/destroyer/corvette/dreadnought/etc role/size thing please? I can't find it anywhere.
As the others have said there is no fixed size to a classification. These are the sizes I typically use, although this is from the pre-6.0 game so I may need to revise them a bit now(my destroyers seem to be running at 10k tons now for example).
FTR Fighter [250 ton]
FTR-H Heavy Fighter [500 ton]
GB Gunboat [1k ton] - FAC engine
COR Corvette [1k-4k ton]
FR Frigate [5k ton] - Defensive/special purpose
DE Destroyer [5k ton] - Offensive
CR-L Light Cruiser [10k ton]
CR Cruiser [15k ton]
CR-H Heavy Cruiser [20k ton]
CR-B Battlecruiser [25k ton]
BS Battleship [30k ton]
DR-L Light Dreadnaught [40k ton]
DR Dreadnaught [60k ton]
DR-H Heavy Dreadnaught [80k ton]
DR-S Super Dreadnaught [100k ton]
MON Monitor [150k ton]
MON-H Heavy Monitor [200k ton]
MON-S Super Monitor [250k ton]
COL Colossus [500k ton]
TTN Titan [750k ton]
LVN Leviathan [1000k ton]
Fighter wings are generally 10, 250 ton Fighters or 5, 500 ton Heavy Fighters
CA-L Light Carrier [10k ton] - 1 wing
CA Carrier [30k ton] - 3 wings
CA-H Heavy Carrier [80k ton] - 8 wings
CA-S Super Carrier [200k ton] - 20 wings
BCA Battle Carrier [20k ton] - 1 wing - extra space goes to weapons/defences.
BCA-H Heavy Battle Carrier [60k ton] - 3 wings - extra space goes to weapons/defences.
Use of taskforces is very much up to your play style.
I'll typically run several taskforces, as I usually have far more officers than I know what to do with.
1 survey taskforce, just the commander + survey officer, accompanies the survey swarm.
1 "Training" taskforce. Commander + Operations with the best crew training scores I have. Pretty much all ships cycle through here upon construction.
1 taskforce for each colonised system. Commander, Operations, Logistics, Intelligence and Fighter Ops if any small craft are in use. Any freighters/tankers that will be operating primarily in-system get assigned to this along with the system defence forces.
1 "Contact" taskforce if I'm attempting any peaceful contacts. Commander, Intelligence, Communication and Public Affairs.
1 taskforce for each battle fleet. Every position except survey is filled.
As pretty much every ship of Heavy Cruiser size and up carries a flag bridge, it is easy to form new taskforces if you split off ships from a larger force to operate on their own in a different system.