Answers

All concrete has cracks. The difference is if it leaking or getting worse. Call the local wterproofing or mudd jacking contractor for a site visit.

Hire a structural engineer to determine if there is a problem that needs fixing.  If there is he will give you a report and or drawing detailing what to do.  Then call 2 or 3 Class A Building Contractors who are in good standing with BBB, DPOR, have sent you certificates of insurance and current references have checked out. Give them each a copy of the engineers report so they know how to qoute the work and go with the one you feel most comfortable with.  

I jsut had a new house built and the concrete foundation had a settling crack that ran from the casement window to the floor.  THe only way we resolved it was to hire a local basement waterproofing company (Crack-X - Natick, MA.) who utilized polyurethane injection to seal/fill the crack from the floor up to the window.  It was rouhgly $700.00 for the job.  Some DIY Kit info I found useful can be found at website:

https://www.youtube.com/watch?v=dggJsJ2f1dU

Hope this is useful.

Thanks.

-- Jeff