Your question is very broad. Whole books can and have been written on this topic.
The right place to start is for you and your wife to sit down together and figure out your goals. Where do you want to be in 5 years, 25 years, 50 years? To quote Yogi Berra "If you don't know where you are going, you'll end up someplace else."
Let's go backwards.
50 Years
I'm guessing the answer is "retired, living comfortably and not having to worry about money". You say you work an unskilled government job. Does that job have a pension program? How about other retirement savings options? Will the pension be enough or do you need to start putting money into the other retirement savings options?
Career wise, do you want to be working as in unskilled government jobs until you retire, or do you want to retire from something else? If so, how do you get there? Your goals here will affect both your 25 year plan and your 5 year plan.
Finally, as you plan for death, which will happen eventually. What do you want to leave for your children? Likely the pension will not be transferred to your children, so if you want to leave them something, you need to start planning ahead.
25 Years
At this stage in your life, you are likely talking, college for the children and possibly your wife back at work (could happen much earlier than this, e.g., when the kids are all in school). What do you want for your children in college? Do you want them to have the opportunity to go without having to take on debt? What savings options are there for your children's college?
Also, likely with all your children out of the house at college, what do you and your wife want to do? Travel? Give to charity? Own your own home?
5 Years
You mention having children and your wife staying at home with them. Can your family live on just your income? Can you do that and still achieve your 50 and 25 year goals? If not, further education or training on your part may be needed. Are you in debt? Would you like to be out of debt in the next 5-10 years?
I know I've raised more questions than answers. This is due mostly to the nature of the question you've asked. It is very personal, and I don't know you. What I find most useful is to look at where I want to be in the near, mid and long term and then start to build a plan for how I get there. If you have older friends or family who are where you want to be when you reach their age, talk to them. Ask them how they got there. Also, there are tons of resources out there to help you. I won't suggest any specific books, but look around at the local library or look online. Read reviews of personal finance books. Read many and see how they can give you the advice you need to reach your specific goals.
Good luck!