If you're not graduating for another four years I'd first focus as much as you can on getting that GPA up. A 2.9 is going to significantly limit your options, and bumping it up while you still have the chance will help your prospects a lot; the fewer courses you've taken the more of a difference you can make, so it's important to deal with your GPA before it's too late. To that end, I'd try to take the easiest courses you can rather than taking courses just because you think they may prepare you for law school, avoid taking too many classes at once, and put in as much effort as you can; seek out the help of professors and TAs, talk a lot in class if there are participation marks, and generally bust your ass. It may be painful now but it will pay off big time for the rest of your life.
As chizzy suggests, the LSAT is also very important, in fact it's probably the single most important aspect of an application. You could start studying now, but that may leave you burned-out if you don't plan on taking for a while and it would take away time from your undergrad studying; yu can retake the LSAT but you have one shot at undergrad, at least in terms of the GPA that law schools will consider. I'd put the LSAT off for a while, but once you've bumped up and solidified your GPA make sure to check out this section of the forum: http://www.top-law-schools.com/forums/viewforum.php?f=6
. It's filled with great resources and has helped many people boost theirs scores.