Well, 'moderate' doesn't give any specific info other than that it could be better (mild) or worse (severe). Usually they will give an estimated size (i.e 3-4 mm). Basically, the disc between your L5 vertebra and the sacrum (S1) is bulging back toward the spinal canal and a little to the left (left paracentral). It is bulging enough that it is apparently encroaching on the left S1 nerve.
Also, the term herniation isn't specific either. It doesn't let you know to what degree the annular fibers have been torn or the status of the nucleus. If the imaging facility still has a copy or you have time, I would have them look at the films again and comment on the size and the status of the annular fibers and nucleus. You paid to have the procedure as well as the reading, so make sure that you are satisfied.
Now, based on the symptoms you describe, it sounds like the nerve is not being impinged very much or the leg symptoms you describe would be more constant or you would have numbness /tingling along that same area. That is good news. Also, the fact that you can perform a full ROM without pain is another good sign. I think with proper RH and workout program, you should make good progress.
The most important thing is to avoid significant spinal loading, with the low back in a flexed position. Also, avoid repetitive spinal flexion and prolonged sitting.
I think you should try to find a good chiro or PT in your area that can not only provide palliative treatment, but also teach you a good lumbar spine rehab exercise program. It shouldn't take more than a few sessions to teach you the exercises.
I would try to explain them, but it would take an article sized reply.
You can PM me a fax number and I can send you a couple.
Also, check with Mike and Eric, I think they have a few articles that discuss low back exercises, but I don't remember the names. Also, search the archives on this site there are a few other low back articles.
How long has this been bothering you?
What part of Ohio do you live in? I grew up in Marion.
Keep me posted.