I can only speak for the French waterways.
The cruising permit - known a "vignette" - can be purchased on line using a debit/credit card by visiting
www.vnf.fr. The site provides a lot of other information, and is the official site for the French waterways. The cost depends on how long you want the permit for, but I recall that there is a discount for early purchase - 10% I think.
The best maps/charts of the system are published in a set of about 12 by Navicarte, and can be obtained in UK from Stanfords - web site -
www.stanfords.co.uk. Apart from excellent charts, they each contain a written guide, brief perhaps but useful, to the area covered.
These days the are a good number of other guides, though without charts generally, and probably Stanfords on Imray would be the best place to get advice. I used to like those written by Hugh McKnight best, and I think some are still published and in second or third editions.
Good luck, and I hope this helps.
John