In general for turkey, the 3min / pound plus 5 min time works. Try that and then use an instant read thermo to check. One good thing about frying is that it will give you some wriggle room on temps. It seals in the juice so if you over shoot some, then no big deal.
Chicken takes 4-5 mins per pound.
I have an oil/frying dial thermometer I use. A candy thermo should work, but I wouldn't use a glass one.
quick Google search lead to this page, which looks like it covers most oils
https://en.wikipedia.org/wiki/Cooking_oil The higher the smoke point, the more forgiving the oil. You can reuse oil if you don't scorch it (i.e. get it near or over the smoke point) filter it, and keep it stored in a cool place, or you can even freeze it. But if you don't fry much it isn't really worth the trouble.
Use a little common sense and you should be fine.
Frying a turkey is nothing to be scared of, but working with open flame, and hot grease does take some common sense.