Pete in Holland MI
I've turned lots of red & white oak. Take the normal precautions about being quick about getting bowls roughed out as soon as you can & no plinth. Dry it slowly. Quick methods have not worked well for me. If your logs are big enough, harvest blanks so the inner bottom lies radially from the log center for some cool quarter sawing effects.
The fore-mentioned lemon is very true. The oak, and contact with cast iron, will turn your hands black. Normal soaps & cleaners will not touch it. A bottle of lemon juice is just the trick though.
Green oak is very bad for cast iron. Green shavings on a nice cast iron top of a lathe/table saw/ band saw / drill press will rust them in several minutes. Cover any tool that may get shavings in it while you are having fun turning. Clean your lathe at the end of the turning session that day with steel wool & WD-40, then spray a light coat of WD-40 on it before you leave.
Happy turning !