Help please

I am new to this business of taking the camera off auto - but I really want to get better at taking a range of photographs. I am going to Iceland on holiday in 4 weeks, and know I need to practice taking night shots with long exposure, so I can capture the northern lights (if they display whilst we visit). So I have been waiting for a nice clear night to try and photograph the stars.
Problems = 1. I obviously have to take it off auto focus, bcz it doesn't know what to focus on bcz it's dark, but then on manual it's dark so I can't see what I'm focussing on either!!!!!!!!!!! How do I do it?
2. How do I best capture the stars? I just went for the longest exposure (ie 30sec), using tripod and remote thingy.
3. Perhaps I should just stick to the day job, delivering babies seems much easier!!

The picture is the 'trial' picture I took first - but the 'star' ones are crap!