Hi,
I am a big fan of early TD - especially Zeit, but I also have a soft spot for their second phase: Phaedra - Encore.
Trying to emulate their style of sequences, I sampled and looped short pieces of their patterns in to my DAW and used Melodyne to discover the pitches and timing. They all appear fairly simple and often use two different patterns that interlock melodically/rhythmically.
Also the sequences themselves often run at a much slower BPM than what they appear at first, the use of triplet delays adding to the complexity and note repetition.
I have a DVD here someplace of the venerable Klaus Schulze describing how he uses a stereo delay set to two different values to create interest and poly rhythmic variation in his sequences... he sort of mumbles the actual values in a ''secret sauce'' kind of way... so, trial and error and experimentation is the key here.
Sorry that I can not be of much further help, I too would also love to see a book solely about sequencers - their history and musical implmentation.
I use the Tip Top Audio Z8000 and the cv/gate out from my trusty old SH-101 sequencer to the Eurorack modular ...Eventide Time Factor and Boss Giga Delay in series for delay.