What shouldn't go in your compost bin?

I've been toying with the idea- I've looked on my local council website. They often do "composting deals" I had my worm bin at a bargain price.
At the moment they are doing the Green Johanna Hot Bin for £50. I may join VC?

That's a great deal! I got mine for £80 with an online voucher (my council weren't doing a deal as they have a free green bin service), but £50 is a steal! They're a bit of a pain to assemble, but there's a useful video on YouTube.

I found I had to add a lot of brown waste such as paper and cardboard, because my garden doesn't produce much - most of my waste is from the veg beds and kitchen, and in warm weather you get lots of condensation and fruit flies unless you have something to absorb all the moisture.