Read reviews even if you are not going to purchase because they give you good information about what to look for.
Be sure you understand the limitations of the test(s) you choose to use.
You can Google a test (put the full name of the test in quotes), but you need to verify the author's/publisher's credentials and the validity and reliability for the measure. Anyone can post a test on the Web, in violation of the author's copyright, so look for a permissions statement.
Expect to find a lot of links to commercially available tools, available only for a fee.
