gettin back to books 

A person with an H4 may seek a post secondary education by converting their status to an “F1” (full-time student) visa. Full-time means a minimum of twelve credits per semester in an institution recognized by the INS. Conversion to a different visa is not necessary is to attend a community colleges. These colleges only give you what is the equivalent of a Diploma, instead of a Degree, but they often the serve the purpose of giving you career oriented education.Since H4 visa holders are not allowed to earn money even on campus by taking up a job. If you want to be on scholarship, your status will change and you will be on F-1 visa as mentioned above.   Children on H4 visas do not need a separate visa to attend school.

You should know that studying in USA is a costly affair, so plan accordingly community colleges are economical when compared to the rest. If you are pursing online or distant education, look out for in-state universities as fee for residents is much less than people residing outside the state. At times, staying on h4 helps as, you can pay the instate fee ( not in Michigan, but some states like Texas categorise H4 visa holders as state residents), if you convert to F1 then you will have to pay more. 

To get assistantship or to take advantage of optional practical training, you have to change your status from H4 to F1 by filing change of status application with INS. It may take 6-9 months for approval. You can start attending school while your application is pending. But you can get assistantship only after F1 approval. When you travel abroad next time, you have to get the F1 VISA stamping. The time you spent on your F1 will NOT be counted against your 6 year clock (Eg: you can be in US for 8 years (3 years H4 + 2 years F1 + 3 years H1B)

Scholarships: there is some confusion if scholarships based on merit / grades are considered income for IT purposes, Talk to your spouse’s employer’s immigration attorney.