Hi Jakob - welcome to IIS!
All of the above advice is sound - especially wrt joining the ASV.
Additionally you may want to consider attending an Astro Camp or Star Party. ASV run them reasonably regularly and there is also the Snake Valley Astro Camps (which I can personally recommend). Attending one or more of these will provide you with the opportunity to see first hand what others do and the opportunity to to talk with them at length about their journey in astronomy and AP, and what you are hoping to achieve.
Personally I wouldn't buy any additional gear until you've done some more research and/or attend an astro camp or two. In the meantime keep saving!
Phil Hart is with the ASV and also runs workshops and weekends away - all based on exactly what you're doing - AP with a DSLR. You can find his website and contact details here:
http://philhart.com/
The next Snake Valley Astro Camp, weather permitting, is Melbourne Cup weekend. See:
http://www.iceinspace.com.au/forum/s...d.php?t=145840
I have learnt heaps from the guys at SVAC over the past two years from the camps I've attended.
All the best with your AP adventures.
Paul