IFR class E

I'm VFR and have some questions about IFR.
I've been toying with the idea of pursuing an IFR rating, especially due to
the recent (uncharacteristic) fog.
I've only flown real in IMC once.
I was at a class D airport, and the CFI got clearance before takeoff.
He got all kinds of instructions for going up through the soup.

I'm wondering how that works at a class E airport, like the one I'm based at
in Minden, NV.
For example, if there was real IMC (a fog layer at 300 AGL), would you be
allowed to take off?
If so, what would be the procedure?
How would you ensure separation from other traffic?
The closest tower is Reno, but they wouldn't be able to get any radar fix
until you climbed to about 3500' AGL.

Similarly, for landing (assuming a GPS approach is approved, there is no
ILS, etc).
What would you do once Reno lost radar contact?

Thanks,

Adam
N7966L
Beech Super III