Secretarial Services . If you're campaigning on a lot of issues you won't have time to become expert on all of them. You might want to focus on just 1 or a small group. For the others the Fact Sheets in the issue files should be enough. Too much information can actually reduce your efficiency.
General summaries are much better.
There are others. General References You might want a dictionary, thesaurus, atlas, a detailed map of your city, and others. It depends on your campaign. Equipment Stationery You'll need a complete set of course. Leave them as few openings as possible.