Granted, 100 a day is low wages. But look at it as an opportunity to learn and get paid a little for it. Very little, actually, but you have to start somewhere.
100 a day gross is probably going to be 70 a day net. Are you working a faller's day or will you be working eight or ten...or more?
You've had some good advice here but I'd add one thing. You're not a faller, not yet anyway, and you need to remember that no matter what your boss wants you to do, your main concern should be keeping yourself safe. If you get into a situation that you're not comfortable with, go get your boss and have him walk you through it. If he's any kind of logger at all he already knows you're green and if he's a decent guy he'll help you learn. It benefits him if your skill levels increase.
If it turns out that your boss is a flake, if he runs junk equipment, if he doesn't pay, if he doesn't keep his word, or if he puts you into dangerous situations and demands that you either perform or get yourself gone...just pack up your stuff and go. There are other jobs and other learning opportunities.
One thing about it...you're going to find out that there's a big difference in getting to cut wood and having to cut wood.
Let us know how it works out for you.