Hey /fit/If my left arm is really painfully stiff from dumbells, should I leave it to recover for a while, do fewer reps until it gets stronger, or just plough through it carrying on how I am now?
you need to eat more dumbbells.
recover
Oh, also: it's the bicep that's stiff, can I carry on doing the tricep exercises or does I has to stop everything for a few days?
Recover and stretch.
Recover a bit , if you train everyday you wont really gain much more muscle since your muscles are overused. The muscles only grow in the "recover" time while you sleep.