I did this two or three years ago during the easter hols.
We started above Hay, hiring the boats from
Wye Valley Canoes who provided us with excellent service. They even gave us laminated information cards detailing the sights on the route and camp sites.
If you start this high up you will get to know the river quite well, -lots of wildlife and tributaries, but few other canoists. -Most of the time it felt as if we had the river to ourselves.
Summer water levels are a little low for a really good run from this far up, so in the larger pools you could feel as if you are paddling forever and getting nowhere. There were only a few mildly exciting spots between Hay and Hereford where we got out.
There are several places to camp on the way either legally or otherwise.
The company provided us with boats and paddles (obviously), bouyancy aids, laminated notes and barrels for our goods. I would add to the list and take:
One light rope for tying the boats up and possibly to help getting up the bank.
Stove -Brewing up mid river is fun!
Sandals -Dont go into the river in shoes, your feet will stink forever
Hat, sunglasses and bug protection.
Important advice:
1: Always wear the bouyancy aid
2: Always tie the canoe up well when getting out for a break
3: Dont let go of your paddle (its embarrasing)
4: Get wet, Have fun.
The UK Rivers Guide may also be of assistance.