There are three types of vouchers:
Breakfast: good for any sitfown breakfast including the character meals(not Swan/Dolphin) and these are 17.50
quick&casual: these are good for almost all the counter service restaurants at the parks(except some carts) and many of the food courts in resorts. Good for one entree, side, drink, dessert for 11.25
Kingdom luncheon: good for sitdown restaurants in parks/resorts but only for lunch. They are 27.75 or so.
We have used the breakfast and q&c and love them. Nice to have some meals pre-paid. CM know about them and you don't have any problems using them. They also include tax and gratuity so they are good deal in that respect.
The connecions123.com website does not tell you alot until you join.
We are connections members (yearly membership was $79.00)and have always had great service from them; although others have had issues. If you join for a trial $1/one month, make sure you cancel on time or they will charge you for the year. You can buy up to 40 of each kind of voucher per year. Others told me that they will be increasing the yearly fee significantly and if they do, I may not rejoin. They also have great discounts on park passes at IOA, US and WDW along with Blockbuster, TOYRUS and other restaurants so we have gotten our $79! Hope this helps. We have seen people selling these vouchers for WAY over value at e-bay..I don't recommend that. IMHO
Connears
I'll have to see if I can convince my friend in NYC to join and get me a couple 
