Let's say I exchange links with another website, except that on my website I "nofollow" the other website's link - is this classed as a one way or two way link on my part?
No This is called only as a Link Exchange means two way links. Always take care before link exchange that link should not be "nofollow".
Cheers guys. So if someone clicks on a "nofollow" link on my website, does this click get tracked as a "referred" link from my website?
I suppose it is still technically a 2 way link although if you no follow then your site will pass no pr through the link
If you use nofollow then why should you engage in 2 way link exchange? I suppose it is a one way link then.
It would be considered a one way link since you are using nofollow. I would let the other webmaster know that important fact!