My partner took us here on the way back from a holiday - as he had been brought here by his father as a child. The place is easy to find if you travel along either the M54 or the A41. My partner was more than delighted with the changes he found, and I, as a novice, with no previous interest in airplanes or the RAF was totally impressed too. This is definitely worth a visit, even if you don't think planes are of interest to you.
It is Free entry, with a pay & display car park. However, we ended up spending about £40 overall. The reason: we didn't bring a packed lunch due to lack of planning, and the museum shop was so good we just couldn't resist ! Incidently, though the restaurant was a little bit expensive, we did eat some very good sandwiches. The shop was amazing - one of the best souvenir shops I have ever been forced to go through on exit from an attraction. You might want to plan to bring some money if you like doing a bit of pre-Christmas/birthday present shopping.
As for the museum - we couldn't get the best from it due to having young kids in trail. There is a lot of information on the walls and on signs, which is most likely really interesting, but we just couldn't devote the time to, which is a shame. I picked up, in passing, a story about a female Test Pilot of the 1950's which sounded amazing. That is why I would like to return again in the future. However, this frustration is more than made up for by the planes themselves. You get to walk through hangar after hangar filled with them and such a variety too. They are beautiful things.
In the first hangar, there is also a hands-on science bit which kids love - where they jet to poke ping pong balls through holes and watch them fly up and float, or they can use handles to simulate operating a hovering helicopter.
You get to see test planes, war planes, bombers - and stand right beneath the hatch where a nuclear bomb was held, passenger jets and helicopters and lots more. Wish there'd been more planes you could climb into and see the inside of, but there you go.