Get started now
The 7 to 15 mil oversize suggested by others seems good to me.
European BizSolutions SLNEU
For most through-hole parts, I specify .035" finished hole size. This is suitable for DIP ICs, 1/4 watt resistors, small transistor and capacitors.
You need the pin or wire to be able to fit thru the hole, tighter is better.
PCB Instant Quote