Bike Forums - Local Mancunian Knowledge Required Please!

I'm planning to bike from Manchester airport to Leeds and then on to York. I love canal paths (traffic free, good for stealth camping), but I'm having trouble finding the best canal. There are indications that I might be able to take the Liverpool Leeds canal, but I'm not sure tow paths are open for bikes all the way. I've also heard the Rochdale canal is great for bikes, but is seems small compared to the other.

Are the canal towpaths open to cycling? Has anyone done this trip or suggest an alternate (I could for instance take a train somewhere from Manchester airport).