The visa is good for a year but your allowed period of stay is whatever was stamped into your passport when you entered (should have been 90 days and will be indicated on your entry stamp).
Your options:
a) exit and return every 90 days. Effectively this can give you 15 months stay in the kingdom.
b) get the paperwork together to "extend" your period of stay from 90 days to 1 year but this will take even more paperwork and a hefty bank account.
Going down the EDU visa route just complicates the whole process when it doesn't need to be.
.
Enter on a SETV (60 days + 30 day extension... gives you 90 days to get sorted).
.
Find a job.
Once you get your non-b and work permit you can put your husband and baby on non-O visas and all of you can get an extension of stay to match your contract.
.
As long as you stay with the same employer you simply get the annual extension of stay (b1900 each).
.
If/when you change employers then a quick visa run to get new SETVs for the 3 of you and start the non-B process all over again.
For a non-B with a 1-year extension based on a work permit then a 3-month extension is possible. The cost is b1900 for the visa plus the cost of the work permit extension
AND
all of the associated paperwork needed to extend both the WP and visa.
If you are working as a teacher then that may also include the necessary paperwork to get a new teacher's waiver from Khrusapha (no fee but time is needed).