How do I claim 3500 expense paid for my son after school tuition?They don't give any tax document

After-school care for an eligible dependent under the age of 13 which is provided so that you can work is claimed as Child and Dependent Care Credit.  The school may not provide you with an official tax document, but you will need the Federal ID number for the school in order to claim the credit.

Use the following steps to get started:

• On the top row of the TurboTax online screen, click on Search (or for CD/downloaded TurboTax locate the search box in the upper right corner) 
• This opens a box where you can type in “child and dependent care” (be sure to enter exactly as shown here) and click the magnifying glass (or for CD/downloaded TurboTax, click Find)
• The search results will give you an option to “Jump to child and dependent care”
• Click on the blue “Jump to child and dependent care” link and enter your information

To learn more, take a look at the following TurboTax help article:

What is the Child and Dependent Care Credit?