Hi
@Bigal26,
The first bike 'tour' I did, with a buddy, was from London back home to Sheffield (mostly) along the waterways. We were aiming for three days, so a little over 60 miles a day, and distances neither of us were especially used to. It was a ... learning experience!
Having narrowboated, we were familiar with canal infrastructure, but hadn't appreciated how different it could be from the saddle of a bike. Unlike some of my fellow responders on here, I do think the landscape changes and there is plenty to sustain interest. We didn't bother with a map and determined in advance the places we needed to hit and how to negotiate the canal junctions we'd meet. We booked B&Bs for our stopovers, though as other folks have said, the opportunities for (stealth/wild) camping are plentiful if that is appealing. There are canalside cafes and pubs from which to seek refreshment, but it would be smart to know where these are in advance; being rural, some of them are closed during the day.
There were a couple of factors we'd simply not considered and which proved real challenges for newbie tourers. Firstly was the sheer number of obstacles we met which interrupted our pace. In heavily populated areas (for much of the stretch through London and its dormitory towns) there were pinch barriers aplenty meaning you were forever stopping to manhandle the bike around or through them. Elsewhere along the canal, there'd be crossover bridges or locks where staying on the bike was difficult or impossible. It was sapping being unable to maintain an even pace. What was far worse however, was the condition of the towpath on more rural stretches. We were fortunate to be in the middle of a dry spell so the towpaths were rarely muddy as earlier responders have suggested, though having travelled and walked widely on the system, they are definitely right to point out how bad that can be. Our problem was the (literal!) pain in the rear caused by long stretches along uneven terrain, whether tussocky grass or more often, tree roots. These of course also slow you down from trying to avoid the pain, and from avoiding the potential for accidents as others have described. So much was our pace reduced, on two days of the three, in order to get to our B&Bs (no mobile phones at the time), and simply from sheer exhaustion, we <oh, the shame!> caught the train for last ten or so miles. That's a bonus of course; railways often follow the same path as canals.
Don't get me wrong, I love our canal system; as novices, we'd just bitten of more than we could chew. My advice would be to prepare for travelling at far slower average speeds than would be possible on roads. If we'd taken four days instead of three, I think we'd have been fine. Oh, and don't forget chammy butter!
Enjoy!