Since you said there were no controls, I'm assuming that means no volume controls in any of the rooms.
So, you would need a speaker selector with volume control like this one:
4-Channel A/B Speaker Selector w/ Volume Control - Monoprice.com
Note! Read the reviews on that one, it is pretty inexpensive.
Instead, try eBay - something like this is a steal if you get it for under $100.
Niles SSVC 4 Black Four Pair Speaker Selector Volume Control | eBay
Now, you didn't mention how you listen to audio. Is the living room where the TV is? If so, that may change things a bit, as you may want a surround A/V receiver for in there, and then a zone-2 feed for the other 2 speaker pairs. You would also (generally) add a center channel and a subwoofer to this type of setup if it is properly configured for surround sound.
There are a bunch of questions which should be asked, but I'm going to just make some guesses and give some recommendations.
1. The Living room is setup properly for surround sound, but only has 4 of the 6 speakers used for 5.1 surround sound. You will need an A/V receiver to handle these properly.
2. The other two zones are normal stereo zones and will require a speaker selector with volume control and a zone-2 output from the receiver, preferably a powered one.
3. Something like this will do you well:
Onkyo TX-NR515 7.2-Channel Network A/V Receiver | Accessories4less
4. Add a center channel and subwoofer later if you want to complete the living room setup.
5. You will need to run analog audio (red/white rca cables) for anything you want in zone 2.
6. The zone 2 output will feed the speaker selector/volume control to allow you to listen to any of your sources in the dining room/bedroom.
7. The dining room/bedroom will play the same source, but the rooms will have individual volume control and can be turned on/off independently.
8. If you want separate source selection for the dining room/bedroom, then it'll cost you a fair bit more.
9. Total for what I have listed here - about $400 including the cabling you will need (
www.monoprice.com)