I recommend to check varroa every month and a half (every 45-50 days). And then do the treatment if needed.
Varroa Mite check
Bee smoker is important tool in beekeeping, make sure to choose the right smoker with fire prevented shield.
Mite away quick strip
Mite away is very effective mite treatment but if missuses can be dangerous, you must follow the direction. For smaller hives I would recommend to use 1/2 of the dose( just 1 strip). Can be applied with honey suppers on.
Vented Beekeeping Jacket
A good vented jacket is very important especially here in CA.
I recommend this jacket
Honey B Healthy
Helps Promote Healthy, Vigorous Hives.
Add to your feeding mix to help build up packages, nucs, and swarms.
The Backyard Beekeeper
An excellent introduction to small scale Beekeeping.