I have 3 jacks. All three jacks have separate wires which go to the telephone network interface box outside the house. I have disconnected all three wires from the box. I've attached a photo that shows what's at the NIB now - 3 separate wires, each going to a different jack. The wire types are older. The wires on the left and right are some kind of hybrid "quad" wires containing red, green, black yellow, blue and white wires. The middle wire bundle seems to be standard quad wire with just red, green, black and yellow wires.
Currently, I have my Telo connected to a wall jack (specifically to the wire bundle on the right in the photo), and using a splitter/duplex adapter I connected the wall jack to a phone. I have the Ooma dial tone on this phone.
But I'm not sure how to connect the other two wall jacks. I've seen the instructions "Distributing Ooma to all telephone jacks" on the Ooma web site and it looks like the wall jacks have to be connected in series to each other. But one of the threads on this topic - viewtopic.php?f=2&t=14093 - makes it sound like I can just connect certain wires of the three wire bundles together where they end at the NIB to connect the jacks.
Fortunately, the house is just single family, and I don't have any other electronics (i.e., alarm system) to complicate things. Thanks everyone for your help.
So what you need to do is to connect the 3 reds together and 3 greens toghether (clip all the exposed metal leads off on all wires first). IDEAL 85-925 3 wire butt splice scotchlok connectors from Home Depot
Buy a $5 phone from Walmart. Cut off the far end of the modular plug cord you would normally stick into a wall jack and split the wires from it. They will be typically very thin crappy wires so delicate work is needed. Attach alligator clips to them. Now you have a phone you can easily clip on here and there to see if you have the dial tone you expect, etc.
If that's the case, connect the 2 blues with the 1 red and 2 whites with the 1 green and see.
Bingo! I've now got Ooma to all three jacks. Many thanks for your time and knowledge. Just before I saw your last post, I checked the connections to the wall jacks and discovered that for 2 of them, the red and green wires weren't even connected to the jack, but the blue and white ones were. D-ohh! No wonder I wasn't getting a connection! I was just sitting down to write a reply when I saw your post. Now I'll get those scotchlok connectors and finish the job.