The Sally Gunnell exercises on this site are good for starters. I have been waiting since July for approval of my P.I.P. so had to cut down on the weekly heated pool and yoga at the local MS centre, not enough money in the kitty.
I have bought a Swiss ball, on the recommendation of the MS physio, and even sitting on it whilst watching tele helps to improve my core balance. I have found some basic pilates excercises using the Swiss Ball on the internet and am trying to manage at least one twenty minute session a day.
Another thing that helps for me is slowly walking backwards. I started this up and down the kitchen, using the work top to support me. I know I must be confusing the locals now, as I try to manage about half a mile backwards then forwards on the esplanade at the beach, (weather permitting) Mostly people give me a wind berth, thinking perhaps I am a little crazy, but many are very friendly and intrigued as to why I do it. If I do the backwards first, I find I am much less wobbly on the forward return journey.
Everybody can find their own level, but the most important thing is to try. Surprisingly after about 20 minutes to half an hour of excerise, I feel less stressed and tired than before I started.
Good luck
Mary