What do I do with fuel, distance, and time to descend and climb, on nav log? So I've got my navigation log mostly filled out. All that's left to do is determine fuel to climb and descend. I go to my Archer POH (Pilot Operating Handbook) and use the time, fuel, and distance to climb and descend charts. Got about 1.5 gal for both descent and climb. 8 min and 6 NM for climb, 8 min and 18 NM for descent. What do I do with these numbers?
Realize that both the climb and descent are taken from the en-route section.

I always calculate climb first and determine where I will reach top of climb on the sectional chart. I then calculate descent and figure out when I need to descend on the sectional chart. The distance in between is my en-route section.

From reading your question, it seems you calculated en-route from departure airport to destination airport. You don't want to do that.