storing uploaded photos and documents - filesystem vs database blob
Definitely store your images on the filesystem.  One concern that folks don't consider enough when considering these types of things is bloat; cramming images as binary blobs into your database is a really quick way to bloat your DB way up.  With a large database comes higher hardware requirements, more difficult replication and backup requirements, etc.  Sticking your images on a filesystem means you can back them up / replicate them with many existing tools easily and simply.  Storage space is far easier to increase on filesystem than in database, as well.
My specific situation
Property management web site where users can upload photos and lease documents.  For every apartment unit, there might be 4 photos, so there won't be an overwhelming number of photo in the system.  
For photos, there will be thumbnails of each.
My question
My #1 priority is performance.  For the end user, I want to load pages and show the image as fast as possible.  
Should I store the images inside the database, or file system, or doesn't matter?  Do I need to be caching anything?
Thanks in advance!