Hey there,
I'm no expert, but I've heard that doing weights PRIOR to cardio is better, if only because you have more strength to do the weights before your cardio. HOWEVER, I do the opposite most of the time. LOL Not bc I'm trying to be a rebel, but because I just choose to do it that way. For example, here is what I do:
Sun - 4.5 mile run followed by full body weight routine
Mon - short 1.5 mile run
Tuesday 4.5 mile run
Wed - short 1.5 mi run followed by full body weights
Thurs - 4.5 mi run
But this is me. I'm sure the experts would be able to rip that apart, but I don't care. It's what works for me. Personally, I think it's better to stick with a certain routine if it works for you. You are more likely to stick with it if you like it, know what I mean?
GOOD LUCK!