I'm with Grant. Get backups going first, and test restores. Make sure you can actually recover the db.

My second task is usually to look at security and assert some control over the database. This shouldn't take too long, nor should it be onerous, but I've had too many occasions where I start to improve performance and then someone changes something to make it worse. I'm all for changes, but I'd like to know what's changing so that I can understand the

Get monitoring set up. Baselining is a way to do this. A few items for you:

- http://www.sqlservercentral.com/articles/132034/

- http://www.sqlservercentral.com/articles/94656/

- If you don't want to spend time managing/building software, SQL Monitor - http://www.red-gate.com/products/dba/sql-monitor/?gclid=CjwKEAiAxfu1BRDF2cfnoPyB9jESJADF-MdJq8K3fH_ol7V7n9lO1fm5oJ_xU6wopGwkmhd7XRE0CxoCvnLw_wcB (Disclosure, I work for Redgate)

Then go for indexes. If you don't know how things are performing, changing indexes isn't necessarily a good first step. As Grant/Gail mentioned, use Ola's scripts or Minion Reindex. Then as you learn more, look through Jeff's advice.