A.J.
I think your best bet would be to go into a college/university and ask to speak with a guidance counselor about their nursing programs, and they could help you understand timelines, costs, etc. Or you might be able to call and set up a time for them to call you. They might even have an online Q&A forum.
From my understanding, you have to have a bachelors degree to become an RN. And LVN is 2 yrs of school (associates degree) and a CAN is a year long certificate program. If you take more classes per semester than you could graduate sooner. But I'm not sure how you would be able to do that with 2 little ones at home =) rule of thumb is for every 1 credit hr (or semester hr) you should plan on 2 hrs of homework (or at least that's what they told me when I was in college). So a 3 credit class is 3 hrs of class time per week plus about 6 hrs homework per week. A full course load is 12 credits/units, which translates to 12 hrs class time per week and about 24 hrs of homework per week. So you can see how adding even one extra class per semester (a class is usually 3 or 4 credits/units) adds a lot of extra time/work. You can take accelerated classes during the summer though, and that can help speed up your graduation.
You will need to also speak to the guidance counselor about your prior college credits. You will need a copy of your transcripts so they can tell you which courses will transfer and which will not. At the very least your prerequisites should transfer (basic math, writing, etc), which should also shorten the time it takes to get your degree. Make sure the school tells you the requirements for accepting transcripts though. Some require the school to send them to the new school directly, some will accept them from you but with an unbroken seal. Since you have to pay for transcripts, you don't want to do it wrong and have to pay for a 2nd copy!
As I said, best bet is to just contact the school you would like to attend and speak with the guidance counselor and they should be able to help you with all your questions =) good luck!