My experience as a 64 yr old with no previous abdominal surgeries: I was in the hospital 4 days, staples out day 10 followed by lunch out - epidural during/after surgery and no pain meds after leaving hospital. Clothes with elastic or drawstring waist (or no waist) for a couple of months while swelling subsides, then back to regular wardrobe. Size of bag and supplier will be a personal adventure of what works best for you. ET nurse will send you home with a "standard" appliance, but you'll probably want to experiment with free samples from different suppliers. You'll have no control over when or how loud your new stoma passes gas - it will be more frequent during the early days. Your 2 yr old will get the giggles when Mommy's tummy gurggles! Docs may request you modify your diet initially, but after 5 months I eat everything I did before surgery. Key is portion control (too much cantalope made a big mess recently) and advise to chew really well.
Now.. for some of what you didn't ask. Depending on location, the colostomy will give you a formed, rather than liquid, output. More time for food to digest and solidify in the intestine = more normal movements. Irrigation is a possibility for you. The risk of hernia is everpresent and should be discussed with your docs and ET nurse. The healing time for this long, deep, incision is a frustratingly long time .. 6 months at least, and maybe up to a year, my folks say.
What I see as your worse post op problem will be the restrictions on lifting. You are a young mom with two small children - who is going to be there to pick them up, lift them down off places they ought not be, even into and out of high chairs? Who is going to load the groceries into the car, bring them in, lift the heavy jug of laundry detergent, the dirty clothes basket, etc? You can handle a gallon of milk .. but not much more. I couldn't even pick up the cat for awhile! Be very careful about doing too much too soon.
My permanent colostomy in 2/06 was due to rectal cancer. It literally was a lifesaver. I've been truly blessed... Cancer free with no chemo or radiation, just surveillance.
Since you have a little time before your surgery, check into all the boards online - United Ostomy Association of America is a good place to start, plus Ostomyland and many others. The more informed you are, the more proactive you can be, the more you will listened to and respected by both your caring family and friends as well as medical staff. 