First time Germany.

Tinribs

We (husband and I) are taking our little caravan over on our first European trip this summer. We are also taking David's 87 year old mother! We were thinking of travelling through Benelux to the southern parts of Germany, then back via parts of the Netherlands.
Any suggestions for routes and ideas would be welcome. I'm also trying to decide whether ant of the camping cards would be useful. We have to go in August, so am assuming the sites will all be high season prices with no discounts anyway. A long post with lots
of questions!