"Open source skills are going to be in high demand next year, as Linux continues to be a market with double-digit growth, year-over-year. Cloud infrastructure is emerging to an open source model as well, increasing the need for related skills. Also, with developers increasingly going into mobile and social-related projects, developers with an interest and passion for open source will be highly valuable for the large vendors, such as SUSE. This not only applies to developers, but for sales and marketing staff."
"We believe that any previous development, sales and community experience is important, which includes volunteer work. The key is for our employees to be experienced and passionate about open source, so community involvement is an important factor in our hiring decisions. We also value employees [who] are willing to embrace a global corporate culture, with much of our workforce and clientele spread all over the world."
What kinds of salaries? That's another "It depends" answer. Salespeople usually have the most opportunity to make lots of money. For everything else, very generally speaking, expect family-wage incomes from $40,000 to $125,000/yr for technical positions, and more for management jobs.
Where to start?
Where are the jobs? As with any job hunt, getting to know the industry and developing relationships is the best way to find something you'll really like. There is a whole Internet full of forums, mailing lists, and social networking sites where you can dig up all kinds of useful intelligence. The big job boards like Monster might help, but I think it's better to identify the companies you want to work for and target them. Red Hat, Novell, and IBM are the big three commercial Linux developers and vendors. There are also multitudes of smaller, independent shops; everything is online, and discoverable.
While code may be your resumé, as McPherson pointed out, it also also applies to whatever your interest is, whether it's documentation, sysadmin, community manager, etc. Think of it as "reputation management," proving yourself by doing. Become a Linux user, learn your way around the vast Linux world, and then pick a project to volunteer a little of your time to. There are a number of projects that are friendly to beginners, such as: