I have a small jon boat with an electric motor and fish small lakes that are no more than 10 feet deep. Should I get a fish finder and if so what kind? Is a side imaging model worth while or should I get something basic? I am trying to locate structure and deeper spots in muddy water most of the time. 

I wouldn't bother if only ten feet or less JMO 

I don't care if you're fishing 10' or 100' you should be fishing structure...that is if ya wanna catch!

 

Side imaging or down scan aint necessary.

 

I recently replaced the one on my Jon Boat with a Lowrance HOOK2-4x GPS Bullet, basic fish finder & GPS system, offering Wide-Angle Broadband sonar & a GPS plotter.

 

Color dual beam sonar and GPS should take care of what you absolutely need. 

Even the most basic sonar will help improve your catch as well as teach you about fish location and behavior.  For your rig, keep it simple with a traditional sonar unit like an entry/mid level Garmin or Humminbird and learn it first, then move up when you upgrade boats years down the line.  Have fun!

Thanks for the advice. I am thinking of getting a low end Garmin and see how it goes. 

What is your budget and how serious do you like to fish?  Something like a helix 5 is good bang for the buck. 

 Two or three times a week as long as weather permits. Is side imaging worth the extra money? I fish shallow water. I guess you can tell what my budget is as I'm fishing from a 10 foot jon boat.

I have a garmin striker plus 4cv on my kayak. It's only $180. Super easy to read and use. Not sure if you have a trolling motor or not but it comes transom and trolling motors.