1) Prepare your resume. Apart from mentioning in your resume your employment experiences before you became a stay at home dad, you must include in it any volunteer work or academic and extra-curricular activities you've accomplished with your kids. This has nothing to do with your employment skills. But this gives your prospective employer an idea of your soft skills and about how meaningful you've spent your time.
2) Ask the help of everybody. Let all your family members, friends, acquaintances and neighbors know that you're looking for a job. This is something you shouldn't be ashamed about. You will have a bigger chance of getting more employment opportunities if everybody helps.
3) Join professional organizations. This is key to knowing people in your profession. They can provide valuable recommendations for your job hunt. Moreover, these organizations provide free seminars and training sessions that help you improve and learn new skills. That would be good to see in your resume.
4) Share what you've learned from staying at home for some time. Since you've been dealing with your kids and the chores for some time, you're most likely to have a lot of patience when accomplishing tasks. Also, you might have mastered time management and some organizational skills. These could all be a plus when you're applying for a job.
5) Practice patience. If you left a top position some years ago, you cannot expect to get back to the same position and salary range when you get back to work today. You can choose to stay at the job hunt stage a little longer until a suitable employment opportunity comes. Or, you can take a lower or entry position at the moment and work your way back to the top. Both situations will require extreme patience on your part.
And I finish my post with this fortune cookie message: