In my opinion, it is NEVER too early! I was in your position a year ago - I am now a junior and just took the LSAT in February. I had a little over a year to prepare, which gave me time to take lots of preptests without having to cram - my average was approximately one test every two weeks. Whether or not you should take a course really depends on you; take a few tests and see if your score seems to be going up and if you feel like you are starting to understand things better. You may be the type who can benefit more from self-preparation than a course. I took a course, but felt like it didn't help much (if any). However, at this point, you still have plenty of time if you choose to take one. Best of luck!