Hi,
you don't need to use 10 bit A/D. you can use 8 bit , that is easier than 10 bit.
like this:

define OSC 4
TRISA = %11111111
x var byte
ADCON1 = %00000010
adcin 0,x ' 0is the channel number and x is the variable
end

you don't need to connect the Vref+ and Vref- to somewher.

if you want to use 10 bit ask me again yo tell you.