Change a career

I think that asking about it (yourself and us) means that you are unhappy in the career you are now. So we already know you want to change.
 When is the right time, probably, as soon as possible, given certain conditions. The fact of the matter is that the older you get the harder it will be to get a new job.

So, what kind of things you should think about before quitting your job?

First of all, since  you aren't happy in what you do now, do you have any idea of what you want to do next? would that require going back to school or training or learning new skills? If it does, then it might be better to go to school part time while still keeping your old job.

Second, can you afford the change? do you have young kids or other people who are dependent on your income? are you paying a mortgage on a house? what are your financial obligations? Most of the time, starting over mean having a dramatic pay decrease for a while being that you still don't have experience in the new field. You should either have savings to relay on, or an income from another resource (like a wife that have a job that can support the two of you while you are learning the ropes, or a property you can rent out or an investment).

If you can handle the financial obligations and you know what you want to do now - just go for it!  

As soon as you ask that question of yourself and at least one other person, it is time to change. 

Keep in mind that as you enter a job, you should have an exit strategy for when you lose your job AND for when you wish to change jobs.  Don't leave this up to anyone else.

If you can get more money and at least the same benifits than you should change jobs, unless you work for yourself.

When tears well up in your eyes as you get into your car to go to work.

When getting up to go to work is a heavy burden on your Soul.

When you find yourself looking out the window and knowing there is something more for you and you should just pack it in and pack it up and for crying out loud it's your life live it and get the huck out of the muck and mire.

Sighhhhhhhhhhhhhhhhhhhhhhhhh  It is not that hard trust me.

Listen to your thoughts and your interests. what moves you? what do you like and dislike at your job? what do you want to do?  

There is a nice qoute "Middle age is when your age starts to show around your middle."

The help I can share with you is with your next job interview. you may find good stuff here - Most Common Job Interview Questions