My wife and I returned from a 3 year tour in Germany at Landstuhl in Dec '02. We were both fresh out of nursing school; I was military, she wasn't. Highlights of our personal experience related to your question:
The hiring officials were strict about having one year of experience before her application for a position was considered. She gained experience by volunteering through the Red Cross and working in a contract position in the Walk-In clinic. Long, long, story short: expect to have one year of experience before the Army will hire you.
The CPOL website mentioned before is the best first step. Until you know where your husband will be stationed, your efforts will be best directed towards completing an on-line resume or 'Resumix' that satisfies the Army. Per my wife, this can be somewhat frustrating. Advice: in the Knowledge/Skills/Attributes section, some folks related better success by typing in the glossary from their nursing textbook
, etc. This was due to word matching between the job description submitted by the particular ward/clinic and all resumes in the system. More words, more matches.
There are three main Army hospitals in Germany (Landstuhl, Wurzburg, and Heidelburg) with many clinics. Openings were difficult to find before '02... the additional money flowing into the DOD and the increased patient load at Landstuhl may have given reason to add nurses, though there are Reservists activated to beef up staffing.
Once you get orders and know to which post your husband will be assigned you can narrow down application to a particular medical facility. Keep in mind that Germany isn't small and the bases are not all together. Depending on your husband's MOS, somewhere in the Kaiserslautern Military Community or Baumholder would be best for employment at Landstuhl. I'm not that familiar with Wurzburg or Heidelburg.
Hope this helps. Feel free to PM with any other questions.