I read the first book of the chronicles when I was 13, having found it in a second hand book shop. It had a huge, slightly disturbing impact on me. This was 23 years ago. Five years ago I stumbled across a secondhand bookshop that had all the books in and i snapped them up on a slightly nervous nostalgic whim. I was swept away. I read all 6 books straight through, now that's a lot of reading and I suffered withdrawal when I finished them. They are magnificent.
Personally i think the fiirst three are the best. The second trilogy gets a bit lost in what I feel is 70's dippyisms, but good nonetheless. Imagine my shock then when i stumbled across the new book in my local bookshop last year (in my mind mr donaldson had been long gone, a writer from another age) . I immediately bought it and devoured it and then scanned the internet for the next two, horrified to see that there was no confirmed release date. Until now. I can't wait. I think that the first book of the third series was a return to the grittier style of the first three and retains the integrity of the series entirely. I am 36 now and am excited like a little kid for the next one to come out and congratulate Mr Donaldson on lying low for so long. If you want to appreciate this boook fully, sorry, but get the previous, sigh, seven and read them, then read these. You will not regret it. (tip; second hand bookshops are chock full with them every where, but so is amazon). Though I am sure you could just read these new ones as the set up is slightly different.
If you enjoyed these and want to read something while you wait, search Asimovs Foundation series in amazon and read them. Equally enthralling for nuts like me who are not content with one book, but want to enter a whole new world. highly reccomended.