I took Logic as part of my undergrad Philosphy curriculum - and it was surprising how helpful it was to if p then q the logic questions on the LSAT. That said, only take a class if you think you'd like it - it's kind of like taking a math course.
If you do take a logic course, think about taking an introductory course in symbolic logic. Symbolic logic is the more math-like type, and it can be a little freaky to look at, but it isn't any harder than a high school math class. The majority of what you'll learn won't be directly applicable to the LSAT, but the process of learning to transcribe natural language into symbols that can be governed by formal rules helps you think more clearly. That skill makes it easier to separate the structure of an argument from the content, and I found that helpful on the LSAT.
At my school, the course was just listed as "logic" or "elementary logic." But if you read the course description, it would mention symbolic logic in the description. So look for that. The course will probably be offered in the Philosophy department.At my university, they also offer a course entitled "Practical Reasoning," which is also a logic course, but it's different from the symbolic logic - sort of prior to symbolic logic logic - they only do a little of symbolic logic towards the end. However, in that course there's a lot of problem solving, very much like the ones on the logic part of the LSAT. I never took that course, but people who have, told me that it was extremely helpful in preparing for the LSAT. So keep an eye out for something like that at your school too.