I was wondering if anyone could tell me any possible fixes for a crack in my wood steering wheel.

 

You can get repair kits from restoration parts house's like Year One etc. Or some of the bigger parts chains. I have used them on a few cars. Follow the instructions and take your time and the results can be very good. However the kits are not cheap. $75-$125. Maybe a bone yard replacement would be cheaper. But then you have to worry about the air bag when doing the swap.
Rcad

 

With these products is there a chance that I will get varnish all over the leather. I'm not the most skilled carpenter.

 

If you don't mind leather you can get a real nice leather wheel wrap that you sew on for under $30. I did 2 so far. One on a Explorer and one on a 70 Buick. Take your time and keep the seam in line it looks factory done.
Rcad