I had an idea to turn a remote control tank into a programmable dolly for use for timelapse photography or video.
Why? Because a tank has forward/back movement as well as a 360° rotatable turret.
My question is; would an arduino be a good way of creating an interface between laptop and tank in order to program movement over a period of time with high precision?
Also how difficult would this be for an absolute newb?
What might be a better platform (unless terrain is an issue), would be an old Roomba. Everything's already in place (sensors, motors, encoders, etc), and they are easy to interface to and control (well, at least the old ones are - I haven't actually looked to see how easy it would be to interface with a 500 series or newer).
Contrast that to your tank idea; while doable, in order to get the "precise" control you want, you would need to add the encoders, motor drivers (or interface to the on-board/included drivers - which may be servo-command based) plus do all the control programming and such - a much larger (and more error prone) task. Certainly worthwhile, though, if you are looking to learn robotics - but if your goal is a camera dolly, you will already have a ton of other challenges (programming the motion being a large one). Using a Roomba as a "shell" (you'd want to remove/bypass a bunch of the vacuum parts, as they aren't needed), you could concentrate on the programming almost from the get-go (like I said, I don't know about recent models of Roomba, but earlier models used a fairly simple serial protocol; you would just need to get the Arduino attached via the serial port).
Old Roomba vacuums can be found cheaply on Craigslist, as people tend to run the suckers until they are so clogged up with hair and dirt that they don't run (well, the suction fan and brushes, mainly), and they can't stomach the amount of "maintenance money" (and/or maintenance effort) you have to pour into one to keep it running well (believe me, my wife and I know - we've gone through 3 roombas and a ton of parts, maintenance, etc - it ain't cheap, but it beats using a real vaccuum!). So they trash it, or try to sell it on Ebay/Craigslist (mostly the latter). You can generally find one for under $50.00 if you look carefully.