Hello!
Right then, if your planning on doing it one day you'll need about 18 hours, I know others say less but its 130ish miles and I find a speed of around 8-10mph average is the best you'll get. There's some sections near the summit which are not better than a small muddy path and a speed of 6-8 is more likely, and frequently in the more urban areas you'll be going at the same speed whilst passing people. Your better of doing it in two long but easier days, gives you time to stop and enjoy the sights of the canal. Also seeing as you live in Burnley thats an idea halfway point.
Invest in a good pair of overshoes, and try not to use a rucksack as the constant bumping will destroy your shoulders (I found that out the hard way!) Rear mudguard is a must, front is worthwhile as well.
At one time British Waterways issued 'permits' for cycling, really just a useful item if they ever needed to ban someone from the canals (they can withdraw the permit). Canal&Rivers Trsust carry no mention of it on their website.
Lastly, look around! There's lots of interesting features on the canal, some of my favourites:
Double Arch Bridge near East Marton
A memorial to 7 polish airmen who died when their Wellington crashed at Bradley, near Skipton.
Full story:
http://www.raf.mod.uk/raflintononou...m?storyid=22fa6b17-1143-ec82-2e95146c66d6721f
And of course lots of pubs!
The Top Lock near Wheelton (Chorley)
HAVE FUN!