For your first 600 I would strongly recommend doing one of the established calendar events with a large field rather than a DIY.
One of the biggest benefits of these rides is the advice you get, when you need it, from people who have done it before, a few words at the right moment being worth more than a book-full at any other time. Also a 600 can be a hard and lonely journey, even during a big event. It's a big help when you find someone with compatible speed to ride with during the night sections. Overtaking others on the road, and being overtaken also provide occasional lifts.
Also many of the calendar 600s will have food and sleeping facilities at some point.
Other than that, I'd also like to do a section of the Eurovelo 6, from Nevers to Budapest perhaps. I haven't done any touring in a good while and my bike's beginning to sulk!
Could someone please explain (in simple words) DIY? I would like to do an SR in 2012, does DIY mean I can set my own course? My main issue is the 600, I have, on recommendation, the Brian Chapman. However if I can just ride 600km it makes things a bit easier
DIYs with company are often easier. Solo ones can test your resolve. I remember a hilly 600 some years ago when it rained so hard that I had to carry my bike through thigh-deep water at one point. In the small hours I tried to grab some sleep, wrapped in an old flaking space blanket, in a damp smelly bus shelter. Giving up, I emerged to continue, shivering and covered in glitter....I would find a DIY 600 extremely tough. It's not just the convenience of proper controls that makes a calendar 600 a more attractive prospect, it's the moral support and camaraderie you get from your fellow riders.
d.
First 100k done ever was Emitremmus a week ago, already considering the 100k "Kennet Valley" and "Start of Summertime". Considering Emitremmus was quite a struggle for me I am going for some more punishment. Hopefully I get enough hill training in until then.
I think next year I would really like to complete a 400k, specifically the Avalon 400.