I inherited not just a database, but about 130 database servers with hundreds of undocumented databases. We have about 115 database servers should have the exact same database but I have found about 115 different schemas even different database names for the same database. Compare the schemas to find out what the differences are and then carefully and with full documentation, implement best practices and then test the crap out of them to make sure nothing else breaks. I also had to fix and document replication. I use Central Management to find other differences and to find out what databases are not doing what they should. Make sure you have backups and then make backups of those backups. I love the having a separate server to test - we didn't have that when I started and yeah, it cause a lot of problems testing databases on production servers.

And learn to live on a lot less sleep for a while. It's been over year and I just found another database server today