[john shand]"If i am using Sony premium 60minute minidv tapes. Should i be shooting in HDV mode or SD?"
You are fine using your Sony Premium MiniDV tapes for both HDV and SD recording. The general consensus is that there's no real difference between using a MiniDV tape that says HDV on the wrapper and one that doesn't. The other train of thought is that MiniDV tapes with the HDV wrapper may be less prone to drop-outs than regular tapes. HDV tapes are considerably more money than regular tapes so the choice is yours. But you're perfectly fine using regular when shooting in HDV mode.
[john shand]"Also what setting should i import the footage under. HD (1440 x 1080) or SD 16:9?"
HDV mode is 1440x1080 Anamorphic. SD recording is always 720x480 regardless of whether you're shooting full screen (4:3) or wide screen (16:9). Import the SD recording as 720x480 if you've shot in full screen and if you've shot in wide screen import your footage as 720x480 Anamorphic. Once your SD widescreen footage is in your NLE's timeline the footage will pop out to 853x480.