When the shop does the wheel alignment they will straighten the steering wheel as well....which is what it seems you are talking about.
It's actually pretty simple to align the steering wheel on a TJ yourself if you want to before you go in for the wheel alignment.
In the image below, you will see the drag link attached to the pitman arm....just loosen the two bolts on the collar of the drag link (near the pitman arm). Then, grab a pipe wrench or some channel locks and simply turn that collar. This will expand or contract the length of the drag link depending on which way you are turning it, thereby turning the steering wheel.
Just check where the steering wheel starts...give the collar a couple of turns and then check the steering wheel to make sure it is correcting in the right direction.
Make sure to tighten the collar back up when done....it's harder than it seems to get it perfectly straight depending on how much play there is in your steering wheel, but still a really simple fix.