This is the link to the BRS reef Calculator:
http://www.bulkreefsupply.com/reef-calculator
According to that page the Mg shouldn't be raised more than 100 ppm per day
Ca shouldn't be more than 50 ppm per day and dkh shouldn't be raised more than 1.4 dkh per day.
I've used this calculator quite a few times and it's been spot on every time.
You're totally right, it can be very over overwhelming, but there's lots of help here and there are many willing to share their experience and knowledge. Ask away!