I mailed my tax papers in, how do i know if it was received?

When you mail your tax return, wait about 4 weeks and then you can begin checking the IRS site:

To track your Federal refund:   

https://www.irs.gov/refunds

To track your state refund:    

https://ttlc.intuit.com/questions/1899433

On the IRS site you are also offered the use of an app called IRS2Go