hey Thenel,
I grew up in Knysna, and to try and explain to you where a good fishing spot next to the lagoon is, is going to be impossible.
But what you can do is, when you get to Knysna, go to the woodmillane shopping centre, find the pick and pay. Right opposite the pick and pay you will see two doors with fishing rods on both sides. Grant's sports, go in there!!!!
When you are inside, ask for the old man to help you, his name is Peter Bailey. I think he was born on the lagoon....... no just kidding. He knows all that there is to know about the Knysna lagoon. If Peter isn't there ask for Dwayne. Ask if he has a map of the lagoon and to pin point some good spots, and what bait to use......
A bit of additional advice, when you are in a coastal town for a holiday, never say to the people that you are not local, rather conger up a story and say you just moved here from somewhere not to far away. I use to get the idea the fisherman don't like outsiders fishing on there spots.
hope this helps and good fishing to you...
Phr33dumb