Where to start searching to find more radioactive minerals? I'm pretty new to all this...  

I've recently purchased a Geiger counter, and am hoping to locate rocks like pitchblende and other radioactive minerals for my collection.

I'm based in the North West of England in Manchester and looking for any hot spots nearby for which to go to and search!

Are there maps available, or any hints as to what types of locations I should be seeking to start my search?
You can try using the locality list at MinDat. Go to places that are easily accessible to you and see what minerals have been reported there. If there's something radioactive, it will probably be listed there.

I would remind you that radioactive minerals are, well, radioactive. These things are dangerous. I strongly recommend you find a different hobby. I deal with radioactive minerals as part of my job, and this is not something that you want to do unless you really know what you're doing. I remind you that a lot of the early researchers who worked on radioactivity died because they did not use the necessary precautions.