Hire slow and fire fast. 

Hiring the Right People - Your Most Important Responsibility
Hiring new employee process is very expensive and time consuming, but not nearly as expensive as a bad hire.  Most of the time it is better to hire the right person than to try to manage someone "almost right".

As the IT marketplace suddenly changed, hiring has become the number one concern of most managers.  With more open positions and fewer qualified candidates the pressure increases to cut corners to get productive resources in place.  

When speed is the major need, hiring a contractor as a stop gap measure during the hiring process should be considered. This person might give valuable insight during the hiring process.   

The Devil is in the Details
Have and follow a documented process.  If you do not have at least a checklist, but preferably a documented process, you will forget or omit steps because for "this candidate", you don't see the value.  Admittedly some steps are more important than others in the hiring process, but ANY step can uncover information that could, if know, eliminate a candidate. Due diligence is the key in successful hiring decisions.

Basic Checklist
Interviews:  Plan how many, by whom and what is to be accomplished. It is essential to determine the questions that need to be asked and the attitude and skills you are looking for in the candidate.
Practice the Law of Three. Most unfortunate hire situations will be avoided by taking extra time to thoroughly interview. 
1. Interview at least 3 candidates for each position
2· Interview the leading candidate at least 3 times and in 3 different locations
  (example- in a conference or interview room, in your office, over lunch)
  You’ll find it very interesting how much more you learn about a person when you      meet with them multiple times and outside of the traditional interview setting
3· Have 3 co-workers interview the top candidate
 

Probe Past Experience: Remember that past performance is the best indicator of how someone will do in the future.
1· Check resumes for relevance and accuracy
2· Don’t be afraid to ask detailed questions about participation, work history and achievements taking care to identify individual achievement from the project team's accomplishments.
3· Ask what-if questions about relevant situations so you can gauge the candidate's ability to respond spontaneously. If they are experienced and capable, they should have be able to formulate a viable solution or response.

Reference Checks: Reference checks should be done "voice-to-voice" with direct managers over this candidate. Do not delegate this task. List at least 3 questions that need to be answered to ensure that sufficient information is gathered about every candidate.  Here at PMA, we have form to check references.  Every time we encounter a "new hire challenge".
Reference checking is checking to see "how good' their skills are; do they work well with others; attitudes towards work, management, co-workers; how much supervision do they require; communication skills including listening, verbal and written are considered reference checking.

Creditability Checks: Creditability checking is to help gauge the candidate's honesty. Can you trust what they told you? You can frequently check this on the reference phone call. Checking basic facts like actual dates of employment, verification of title, skills they or their resume claimed they used, what they actually did. You may also want to include certification and graduation verification, background checks, DMV checks and/or credit checks for positions where this is appropriate. 

Is checking references as important as the interview?
Some firms believe that checking the references first is a fast and efficient way to decide who to interview.  A company that interviews dozens of candidates for a single job is not being too selective. Nor does it mean that the job is difficult to fill.  It may mean the company has an inefficient process.  You should be able to know a person's ability to do the job and his or her manageability from the resume, skill testing and references.  WHO is vastly more qualified to judge abilities of a candidate: 
1) an interviewer who just meet the person for a short period of time or
2) a person who has managed a candidate over a much longer period of time?

Why interview if you know someone can do the job already?
You are really interviewing for manageability, to determine their willingness to do the job and the cultural fit with the team. A good hiring process will include multiple interviews by different people.  Three interviews by three different people is optimal for most positions. Since for most managers, conducting interviews is something they don't do often providing some training in interviewing and supplying some specific questions prior to the interview is highly recommended.

One creative idea, keep candidates waiting 5-10 minutes in the lobby seated near their receptionist. You will get great insights from your receptionist before the candidate puts on their interviewing persona. Of course, supplying some basic behavioral observation training, a couple of questions for them to ask will assist the receptionist.  Once the candidate is called to the interview, the receptionist complete a summary of their observations which is forwarded to interviewers to review.

Behavioral interviewing?
Most candidates are prepared to provide a good answer to theoretical questions, both technical as well as how they would react to certain situations.  How they reacted to a past situation is far more relevant. 

"Give me a specific examples of what you have done and how you did it?"  The past behavior will probably indicate how the candidate will perform in the future.  Further question, "Is there anything that you would have changed, if anything, if you had the same situation?"

HR departments know about behavioral interviewing but executives and line managers aren't necessarily are knowable about behavioral interviewing techniques.  Frequently when a impressive-looking candidate is encountered, the manager is so excited that this project is about to be completed, that thy forget to ask good questions, listen to the answers and dig deeper when appropriate.  Successful interviewers try to refute their first-impression bias.

Bottom line
The candidate's past will become your company's future.  The more you invest in learning about that past, the greater your chance of hiring success.  The more you invest in the hiring process, the easier your managing job becomes.