[Prostanc3]

Can anyone recommend a backback or case which is good for carrying books & paper etc without damaging them or fraying the edges/corners?

Ideally not a brief case though as carrying one whilst wearing scruffs etc tends to raise eyebrows.  

[Mat]

A simple method of improving the durability of books in transit is to put them into carrier bags within your bag.
While technically not what you asked if you don't already do this, the results are better than you might expect.

You could try a laptop bag.

[Gileh]

I keep the packaging from amazon deliveries and wrap books in that. You can make larger version by scaling up the pattern with corrugated card. Otherwise I do as above and use placket bags.

[Prostanc3]

Ok so basically wrap my books in cardboard and plastic bags then stick them in a backpack/bag of choice, thanks guys.