Decide who needs remote access and what software applications they will run remotely. Plan to use a product with security features that match the needs of the firm. And, your first setup will go much easier if you bring the remote computer into the office and connect the two together while they are in close proximity to each other. In other words, work out the bugs and procedures in one location. That way, when you do make the true remote connection, you won't be driving back and forth between computers working out the bugs.
Several programs are available to handle remote computing.
Rather than review these products in detail, I'll just name several that are common in the industry. The standard computer magazines periodically review these products. Andrew Z. Adkins III is a nationally recognized expert in law office technology. He is the director of the Legal Technology Institute at the University of Florida Levin College of Law and president of Adkins Consulting Group. He is a founding member of The Legal Consulting Group, an association of independent computer consulting firms working with the legal profession.