Good post !!
Was the sonar new? if so it will have some helpful tips in the box.
Understanding structure is probibly the most important thing you need to learn, it takes time, so don't rush it !!!
Structure is the bottom conture of the body of water you are fishing, it is the most vital part of what fish use to travel from place to place, it's in short their highway.
All fish will hold structure, not all structure though will hold fish, so how do we know which structure holds fish? simple, it's time on the water, you have to make the time to fish and fish often to understand your particular body of water.
In these articals you will find so much information that it can be mind blowing to say the least, just because there is so much of it, but don't pass up the opportunity to read it all.
We all know how to beat the banks early, we often get lost in the thought that this is the pattern for the day, after the bite stops, where do we go from there?
Well if you have found a spot or two with a good morning bite chances are you are in luck, not far from there should be the kind of structure you are looking for, it could be a lake bottom covered in grass, gravel, clam shell, rocks or tree stumps or even a bunch of humps, an old creek bed, road bed...the list goes on and on.
I would suggest using the Carolina rig, this rig is built to find fish and all kinds of structure, you have to use it to get the feel for what is on the bottom, and start using it as soon as the sun comes up over the trees, I would start out using at least a 1/2oz weight, with an 18" leader and matching the bait to what forage the fish are after, it may be a lizard, a grub, a fluke etc...
If the water temp is close or above 80 degreese when your season starts, I would look for water at least 20ft deep, and have multiple points around the location.
Points are one of the most important parts of fishing different structures, if at all possible find a place where two different creeks come together and form part of a mid lake channel or a V in the lake.
Use your sonar to your advantage, scan the area for fish.
Fan cast the areas really well until you find humps, determine what those humps are, rocks, stumps etc... go over it with your sonar and get a picture of what it looks like, if you find fish pay attention to detail, what was your retreive speed etc...make good notes you will need to remember this later on in the fall.
Fishing in the heat of summer is/can be much like fishing the dead of winter, slow, experiment with it find out what they want fast or slow presentations.
If you start fishing structure now it will only make you better in the long run, of course this is only the begining so the info is basic and condenced, but I hope this will help.