Guys,
Some really great info so far, but as requested, here is further info for what I am using.
Source is grounded.
Drain goes to the solenoid (12ohm inductive load), other side of solenoid to 12v.
No protection diode (do mosfets also need this?)
Driven currently by 100ohm from a Kinetis K20 3v3 MCU
100K pull to ground on gate also.
300Hz operation, 20-80%, 50% duty typical
Doing some looking into the recommended part numbers provided.
I appreciate all the information so far, thanks
Matt