Is a filter any good on a rotating lens?

Ok, so I'm very new to the whole DSLR scene, but I've picked my camera & I've picked by Lens. (Sony a300 with 2 kit lenses - 18-70mm & 75-300mm). I've also been reading about filters. I've read that a UV filter is a 'must have', and a Polarising filter would be very useful, as I take a lot of pictures through glass. However, I do know that the lenses I'm getting rotates at the end, which means my filters will rotate - not a problem for the UV filter, but is a problem for the polarising filter. But, is it still worth getting? Is it still going to be usable, but just less functional, or am I wasting my time & money? Thanks!

So when you focus, you will have to adjust that filter (by rotating it). A bit of a pain and that is something you'll get used to in time.

Some lens have internal focusing - the front element does not rotate during focusing at all.

No... you will be fine. The filters are meant to afix to the lenses and because they rotate will not affect the ability to screw into your two lenses. Also you need the Circular Polarizer (not a Linear) that also rotates so no matter what your lens is doing you can rotate the end of the filter and get the best result for your shot. Thanks for reading. Hope it helped.

Most polarizing filters are made so they can be rotated to get the best effect you want. After rotating the lens, rotate the polarizer, then make your shot.

Bert