what pants to wear...

As most of you might be aware, i am in training at present to do the OT next year. i have been researching every aspect of hiking, equipment and such. thing i have noticed it the wearing of denim seems to be a no-no, admitedly not too comfortable but at present is all i have - (only been doing day walks thus far anyway). So what does one wear when one goes bushwalking, particularly for overnighters?
I would also appreciate any info on gaiters, it seems everyone uses them but i cant seem to find any anyway. Dont even really know what they look like.
I would also appreciate any info on gaiters, it seems everyone uses them but i cant seem to find any anyway. Dont even really know what they look like.