Being that Tenn is my first team here, apparently I didn't look at the coaching situation when picking up the team? Who'da thunk it? Anyway I now need to sign three coaches for $160k. I cut about four players but it still says I have $160k for coaches. What am I missing?

Coaching $ is not the same as your salary cap - you don't need to cut players to sign coaches. Instead, if you need to free up coaching $'s, you can replace an expensive coach with a less expensive coach. There is no penalty for firing a coach (which is what happens when you replace a coach)

what is the salary cap for coaches?

I don't think there is one. I asked about the error message stating that the coach offer would put me over the cap and David said don't worry about it.

There has to be as I have been unable to offer over a certain amount for coaches before, sometimes a very low figure, when trying to sign one

I can't figure it out at all. Sometimes it'll show as a really low cap figure for coaches, and then a few spins later it'll show as a drastically different cap number for coaches.

There is a cap for coaches but i'm not sure what it's based on (team attendance/earnings perhaps?).

What you can offer to a coach depends on your cap and how much you are paying the coach you want to replace. If you are paying a large salary, you will be able to offer more than if you are close to the cap and paying the coach you want to replace a small salary.