Yes, it sounds right that you won't have to pay sales tax for a services only business.
Try searching the IRS website for required quarterly filings. My understanding is that you should make quarterly tax deposits on ANY profit you make. I recommend you deposit 18% of your profit to the IRS. And, BTW, these are not TECHNICALLY quarterly. The tax deposits are made in April, July, September, and January of the following year. For more information on basic bookkeeping for your business, check out my archived chat on VAF located
HERE.