If you're husband is offered employment in the U.S. as a journey lineman and manages to retain a greencard through employment, then yes you and you're children will be sponsered as dependents (Depending on age of children).
The length of time this will take all depends on the category your husband would fall under such as EB 1, 2, 3 etc... If he falls under 1 or 2 being extraordinary ability or outstanding etc, etc, then the process will be current providing he has ALL the proper credentials.
Any category after that will take several years starting with EB 3..
Your husband
may require an H1B visa from the sounds of it if his profession falls under a specialty category. The green card bit is not automatic. It's very difficult to obtain if your field of work is not recognized.
I don't believe his profession falls under EB 1 or 2 so the employer would have to apply under EB 3 if they are going to apply straight to permanent residency. Again, this is a long and grueling process so be prepared for a slow and painful wait if anything
