There is no Haynes or Chiltons for a 98. You can get a factory shop manual at helminc.com for $$.

With regards to a mild lift, easiest and IMO best way to go is to install OME rear coil springs. 3 load ranges are available, and all are better than the soft stock springs. They will lift 1-2" depending on which ones you get. I suggest calling Independent4x and tell them what you plan to do with the Trooper and they will recommend a spring for you. Then you adjust the front torsion bars to match the lift. Easy and pretty cheap as lifts go.

Steve Carlson - 95 Trooper LS expo rig
Serenity now!