Start with the compilation Cordelia's Honor. It takes someone who's a civilian working within a typical civilian organizational structure and drops her smack into the middle of a military structure. Warnings however as part of it is set in a war and there is death, injuries, torture, and one on screen attempted rape, so if you're sensitive to any of that do not start there. Instead I'd recommend starting with Komarr as that is much more of a mystery/SF/romance/adventure without much military involvement at all.