Virtual Assistant Jobs--Where to look

I work for a charter school and my position is not salaried. Meaning that I am out of a job, and pay, multiple times a year. The longest stretch being the summer (June-Aug). I was looking for virtual assistant jobs, but I am honestly afraid of stumbling across the wrong hiring company. Does somewhere here know of a reputable and honest hiring agency for virtual assistant? 

I have 10 plus years of clerical and office management work, some accounting as well. 

Thank you in advance. 

Bay935