This is my back yard, so if you have any questions let me know. Best book for the sea bit is the 'North Sea Passage Pilot' which covers both sides of the channel.
There is a distinct lack of info on the Belgian canal system. The French publishers, Navicarte, produce a map of the Belgian waterways, and this will have most of the info you require. It includes lots of useful info, in English, on the reverse including waterway opening times.
There appears to be differing opinions on whether the Oostende - Bruges canal is open on Sundays or not so look out for that. Bruges is a superb place for a visit by boat.
If you have time, another place well worth the trip is Veurne which is on the canal which runs South from Nieuwpoort towards Dunkerque.
Lastly if you plan just an overnight in Oostende, don't bother to go right into the Mercator Yacht Harbour as it takes an age to get out again via a lock and up to 3 lifting bridges! The outer tidal marina is a much better bet.
Have done Shotley to Calais a few times but never Bruges or Oostende.
Don't use any pilot book for this trip but here is the route I use from Shotley.
Medusa to Sunk Head Tower into Black Deep
Then through Fishermans Gat to East Margate
Down Kent coast to South Goodwin and across to CA6 and the approach to Calais.
You will have to time your arrival in Calais since the bridge to the marina only opens HW -1 1/2, HW, and HW+1/2, but in my experience these timings are not very reliable and the Bridge operator is not on VHF.
My advice would be to arrive before the first opening and pick up one of the waiting bouys, then watch for the traffic lights which are supposed to show orange 20 mins prior to opening (notice I said 'supposed to'). The best indication is to watch for the traffic stopping - a dead give away.
The visitors pontoon in the marina (to starboard as you enter) is quite small and if you are forced to moor against the wall opposite beware of a surprising rise and fall. We experienced around eight feet when last there.
When you're ready to leave the bridge opening times are posted in the window of the operators tower.