Interview Preparation

Do you have any tips to help prepare for an upcoming programmer interview?

Are there common interview questions that come up again and again?

Absolutely.

As someone who puts programmers to work, I can tell you that the #1 thing I have recently found is that "self-awareness."

This means that you need to be very clear about what you have and haven't done (Note I did NOT say: "can and can't do." Good hiring managers want a proven track record, not a list of the cool things a candidate would like to do) The biggest things that have blown people out of the water are:
1. putting things on the resume and then not really having used them in a work environment.
2. Claiming to be a "10/10" or "9.5 out of 10" on something, or statements like "oh, don't worry about that"
3. Not supporting (or maybe not being able to support) statements about tools, languages, accomplishments with specific examples.
4. Describing previous jobs like job descriptions rather than talking about accomplishments, outcomes, kudos, etc.
5. Not delving into the opening in a consultative fashion - trying to understand the development philosophy, challenges, department/company goals, etc.

Hope it helps

With the evolving complexity of business requirements and technologies, communication skills are an extremely valuable asset. Doing well in an interview is a combination of what you've already done, and how you explain it. You want to be sure that you come across as an excellent communicator. But, at the same time you want to have the depth of knowledge to back up what you say. It's quite easy to filter out the smooth talkers who don't have any actual knowledge, but claim they do.

Here's a great site with actual programmer interview questions that should help you out with handling the technical questions:

www.programmerinterview.com