When a trip to the nearest county law library starts becoming less and less efficient, it's time to start thinking about building your firm's own collection of law publications. Regardless of your specialty, certain publications are useful as the essential building blocks of your personal law library.
No matter the nature of your work, at some point you'll have a contract issue to deal with. Rather than rely on your hazy understanding from the first year of law school, you should have a good contracts treatise handy. A good start is The Restatement of the Law (2d) of Contracts (West). For an affordable quick reference, there's Rohwer and Skrocki's Contracts in a Nutshell, 7th (West). The deluxe entries in this category are Corbin on Contracts (Lexis) and Williston on Contracts, 4th (West).
Black's Law Dictionary
Let's face it--no one learns Latin anymore. Currently in its 10th edition, Black's Law Dictionary is the go-to reference when you need a basic definition of an unfamiliar legal term or concept. It's available from West in print, on Westlaw, or as a mobile app for an Android device or Apple iPhone or iPad.
Some of the law practice management publications you may want to make a permanent part of your library include The Lawyer's Competitive Edge: The Journal of Law Office Economics and Management (West). Other publications to consider are Law Firm Accounting and Financial Management (Lexis) and Solo and Small Firm Legal Technology Guide (ABA).
Business Organizations and Other Legal Entities
Even if you mainly represent clients in their individual capacity, inevitably you're going to be dealing with a corporation, partnership, trust, or other legal entity. To get a basic, low-cost grasp of the issues involved, turn to the nutshells. West publishes Shade's Business Associations in a Nutshell, 3d and Hynes and Loewenstein's Agency, Partnership, and the LLC in a Nutshell, 6th. Otherwise you're looking at more expensive sets that will give you in-depth treatment of the formation and operation of business organizations in your state, or generally.
You've spent a lot of time researching case law, but can you rely on it in front of your client or a judge? You're going to need some way to verify that the case has not been negatively affected by later law. There are "Shepardizing" products available from Lexis, as well as the major online verification tools available through Westlaw (KeyCite) and Lexis-Nexis (Auto-Cite). Pricey but indispensable.
Many publications are available in print and online on a service like Westlaw, either separately or as part of a bundle. Pricing can vary widely, so compare, and look for discounts. Publications from bar associations, for example, are usually cheaper for members. Pay attention to automatic recurring charges for supplementing or new editions. Also, time your purchase so that you're not buying a publication when a new edition is imminent.