Up to you. For business subjects it usually doesn't matter. For IT ones, usually the tutorial/lab is best after the lecture (and you'll find they usually are). Most of the time, the labs/tuts for IT subjects concentrate on that week's work, so thats why they are after, and because they usually only have 1 lecture.
For business subject's, you'll find a lot of them have 2 lectures, because they are a lot bigger subjects, so the tutorial's will usually cover work from the previous lecture, so it doesn't matter whether you do it before or after. I guess if you do it after, you'll be muddled up with what you just learnt this week and trying to remember last week's stuff, or if you do it before, then you just have to remember last week's stuff, go to the lecture and then learn new stuff. It's really up to you I guess, whatever you prefer. Most people would go after.