If you're going to work on your ST, you need a good service manual. I use the Honda Service Manual as well as the Haynes Service and Repair Manual. You can purchase the Honda manual from Helm in their do-it-yourself section under part number 61MAJ00Z. Helm also carries the Honda Common Service Manual, part number 61CM001, for use in conjuction with the model-specific Service Manuals. You can search the web for it and possibly find a web site that has posted a pdf of it or someone selling a CD of it on eBay. The Haynes manual that I have covers model years 1990-1997 and is ISBN: 185960384X. Haynes later released a version covering model years 1990-2001 (ISBN: 1859607527). Another good manual is available from Clymer, ISBN: 0892877987. A Google or Froogle search will turn up sources for the Haynes or Clymer manuals. Manuals frequently turn up on eBay, too. Search there for "ST1100" and for "ST 1100".
If you are a member of Honda Rider's Club of America, you can access the Common Service Manual and your choice of one Honda Service Manual via their website. (Thanks to Rick Hardy for this info.)
While we're on the subject of manuals, the 1996 ST1100 Owner's Manual is available on-line here. It's nothing like a service manual, but has useful information nontheless. Farther down on the same page is a link to download the Owner's Manual to your computer.
But even well-written manuals are sometimes lacking in finer details of trouble-shooting and repair procedures. Hints from someone who has actually experienced fixing their bike can be really helpful. Knowing this, I've put together this compilation of maintenance tips for common questions regarding the ST1100. It is intended to supplement the information in your shop manuals. BTW, the date of the latest update is indicated for each tip.
I bought a low mileage 1998 ST to part out. Info is here. If you see something you want, make me an offer.