Since Jaxer has been around longer is it a better solution than Node.js if you are a developer like me who is new to programming with JavaScript on the server side?
Despite both using JavaScript as the language, Jaxer and Node.js achieve two different goals. Jaxer appears to be targeted as a server-side Web scripting language (like PHP or ASP.NET), whereas Node.js is more of a general-purpose event-driven network server framework that happens to be able to serve Web pages.
Which solution you should choose hinges entirely upon what you're trying to do. If you can expand upon your question with your goals for server-side JavaScript, then we can provide better suggestions as to what to use.