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. Available from West in print, on Westlaw, or as a mobile app for an Android device or Apple iPhone, iPad, or iPod touch.
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). For larger firms, Law Firm Accounting and Financial Management (Fourth Edition) (Lexis) and Solo and Small Firm Legal Technology Guide (ABA).
So much of the law eventually boils down to money, and where money is involved, so are taxes. You need at least a rudimentary understanding of tax law so you can flag issues for your clients. If you don't want to collect a plethora of issue-specific tax publications or rely on the guidebooks aimed at law students, try a fairly comprehensive two-volume set like Tax Planning Strategies (West). The bigger multi-volume tax treatises are for the tax pros, but if you have a couple grand to spend, feel free to dive in.
Business Organizations and Other Legal Entities
Even if you mainly represent clients in their individual capacity, inevitably you are 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 publishesShade's Business Associations in a Nutshell, 3d and Hynes and Loewenstein's Agency, Partnership, and the LLC in a Nutshell, 5th. 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 various "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.