Coarse Fish In The River Leven

I believe that the month of May is good for coarse fishing on the river Leven. (The one that is situated at the south east corner of Loch Lomond)
I am looking for some information on location, permits, bait, methods, etc
Does any body out there have any information or contacts for information. Hoping to go before the end of the month

The only part i fished was Endrick water. Found loads of good Roach fishing , with odd dace. Perch were good too. Mainly stick fishing, bronze maggot being the bait. Later, i moved places to Balmaha boatyard area and fished the waggler at distance for good Roach and Perch. The place has a few pike around, and the midges are always trying to eat ya, bigtime!