Heavies do more raw damage at higher range but don't track as well. Focused mediums are... just the opposite?

In general -- as with all lasers -- beams beat pulses until you get T2 and access to Scorch. Frankly medium beams are in awesome shape now period.

Well if you're using beams you're usually capitalizing on the longer range of beams in which case tracking matters much less. Up close beams will lose to pulses everytime obviously.

is it really just a trade off between damage and tracking / rate of fire? Will they both hit frigates? I know I read somewhere that a lot of bigger guns won't be able to hit small, fast frigs.

I am new to the game mind you, I am just trying to figure out if both of them will be effective against cruisers and below. I generally go with beams as opposed to pulse because at the moment I am just doing missions for ISK and I find that at least when fighting NPC's, beams seem to be best.

I think Drax is suggesting pvp.... ;)

so what you are saying is for pulses fit the biggest gun you can......well what about for beams?

This is true for every ship, of every weapon system, everywhere, always. If anyone tells you otherwise flex at them and call them a *****. Cram the biggest guns you can get on there. If one shoehorn doesnt work, use two, and some butter.