How much to save out of my checks (1099)

Hello, 

 

I recently started a new job at a private practice. The owner of the practice had me sign a W-9 and stated that I will get an 1099. I work part-time at this private practice. In the past two months I have been averaging 2 hours a week at my rate. However I do plan on reaching about 10-15 hours a week at this job. 

 

My questions are how much should I save out of each check for taxes and when are the dates for paying quarterly taxes? Also, I work full time earn a W-2 at my second job. What ways can I prepare for paying taxes for both jobs? Lastly, how can I find out what tax deductions I qualify for as a part of my W-9 job?