I can certainly fill you in-

True bypass is just what it sounds like. During normal use of an effect pedal most pedals when used in bypass (off) mode allow the signal to pass but not entirely un-affected. In general the signal still passes through a circuit on the pedal and the signal is affected. With a true bypass mod, when a pedal is in bypass mode the signal literally goes from the input straight to the output without passing through the internal circuitry of the pedal at all.

As for Buffers...There are many types of buffer...but used in our field they are a circuit that allows you to match the input signal level of the effects loop of an amplifier with the output signal. While your guitar signal passes through your amplifier's effects loop and any and all pedals or rack effects that you've got in the chain...it drops in strength...a buffer is used to boost the signal level back up to where it should be there-by keeping the signal at the optimum level and not robbing you of your tone.