I have been rummaging around You Tube again and have found some good clips that explain fabrics in a bit more detail.
I have also just found out that denim is similar to a "chambray" fabric and is apparently quite easy to sew. I guess it depends on whether there is lycra in the denim fabric or not though. The message seems to be "always wash the fabric before using it".
I am a bit torn now though, as I thought stretchy fabrics would suit me best because of my curves. Obviously the message is clear - I HAVE to get to work in perfecting the pattern alterations so that having a stretch is not so much of an issue!
I thought this one was quite cheesy and I had a chuckle, but It does give some information too.
Lots to think about!
Hope other people find these clips as helpful as I do.