I have a "vulnerable" disk that goes bad once in a while and then gets better. They do get better but once you have it the first time it's easier to mess it up, so try to practice good back behaviors: these are most important for me —
1) Try to avoid sitting in a chair for long periods of time -- every 20 or 30 minutes get up, take a little walk or up and down the stairs, or alternate between standing and sitting if you can. When you do sit in your chair, don't slouch forward (I just corrected myself now!). One of my friends with a bad disk swears by her bouncy-ball chair, but I've never found one that's high enough when I sit on it.
2) Also try to avoid bending down with a forward curved (flexion) back or twisting your torso. I'm pretty sure that's what did it for me this time because I went to a trainer who decided I wasn't flexible enough and prescribed lots of toe touching stretches. (What kind of bends to avoid depend somewhat on what disk is damaged -- for lower back it's important to keep the natural curve of your lower back and not flatten it out.) Make somebody else pick things up off the floor for you, and even tie your shoelaces if possible, at least for 1-2 weeks. If you absolutely have to get something off the ground, squat deep with your hips and stick out your butt backwards (like a toddler), or do a "golfers bend", stand on one leg and step back with the other, rotating on your hips not bending your back. There is a picture of the golfers bend
here if you scroll down, I can't vouch for the rest of the advice on the page but it fits generally what my physical therapist has recommended.
3) They say nowadays that being "gently active" is better than bed rest, but when I hurt it in my 20s (didn't know it was a disk then) I lay on the sofa with a heating pad when it got bad. I guess it wasn't exactly full bed rest in retrospect since I was in an outdoor environmental course where we did walking and hiking every day!
4) Walking is very good for it if it does not hurt to walk, or you are past the point where walking gives you pain. I have had an episode since about April this time, and earlier this month I had a long distance walking vacation, 55 miles in a week, and it felt fabulous, better than it had in months. Then I got back to the office chair and within two hours, argh, stabbing pains. My PT says the disks do not have a blood supply, so they get nourished by movement: it squeezes the nutrients in and out. I dunno, that doesn't sound very medical but it is true that walking helps me a lot.
5) My physical therapist likes the swimming pool -- "water walking" or bicycling with your legs. I prefer the elliptical -- but low and slow compared to my usual setting -- because the gym pool is always full of shrieking kids. I also use the stationary bicycle, the one with the "chair seat" not the one where you have to bend over the handlebars.
There are lots of exercises on line for "herniated disk" but it's really better if you get supervised by the PT for a least a few sessions, so they can diagnose what movements are best for you. You can herniate different disks or in different directions like Alaskan says. Some people like hot and some people like cold on it, for me it depends on the room temp! I take a course of naproxen (Aleve) for a week when it gets bad, the PT says it's good for putting down inflammation not just pain. Naproxen doesn't agree with everyone digestionwise though, and you can start with something like ibuprofen first.
Good luck!