I've downloaded 2 mods, but I've no idea where to extract them to?

Well, I have Win 7 so hopefully what you have is similar.

First you need to make sure you can see hidden files under your folder options.

Next, navigate to C:(or drive you installed to)/Users/(your profile)/AppData/Roaming/runic games/torchlight/mods

Simply extract or copy the relevant file to that 'mods' folder and restart the game.

make sure the mods you're going to install actually work; since a patch some of them won't be activated.

Ah, thanks! I was looking in the wrong folder. :D