Don't go overboard here... a simple two Resistor Potential Divider will suffice - use 1% tollerance (or better) parts.

Eg... For a simple Divide by 2... R1+R2 can be say 2K2 each, connected in series. Top end of R1 goes to your voltage to measure (input), bottom end of R2 is connected to Vss. The junction of the two is connected to your PIC. Now, 0-10v on the input will be 0-5v at the PIC. With VRef+ configured at +5v Vdd, your ADC will be measuring 0-10v because you have scaled it down.

Melanie