Networking is the key to success. That’s an old adage, but it’s more true than ever. Unless you’ve got contacts for the zillion gigs you’ll probably have during your career, you’re going to have a tough time making much of your professional life. That’s where LinkedIn can help, and help big. LinkedIn is a social networking website that’s got a lot in common with its fun-loving brethren, like Facebook, but that’s serious and very much focused on your professional world, whether you’re a sales executive or a web marketer or an accountant. The tool is particularly useful for those trying to build their businesses, find clients for their freelance companies, or looking for employment. It’s not bad, either, as a way to get back in touch with colleagues from previous jobs.