Two times a month of 10% water changes is good for maintenance. 20% or more good for correcting problems. As far as water paramters go, I wouldn't worry too much about it. They are going to fluctuate drastically until your cycle finishes. On the other hand, I would increase the specific gravity to 1.025-1.026. All the other parameters, don't worry until after the cycle. After the cycle, do a large water change and see where you stand. Here is a great article on water parameters:
http://www.reefkeeping.com/issues/2004-05/rhf/index.php