using :binary columns in models

I am creating little personal flags for each user and since they are
small I think it would be best to store them as a blob (:binary), but
I can' find anything that i understand.

Can anyone point me at a tutorial on handling images in rails?

Yes , You can simply save the image in the database.
Add a column in a table having type BLOB.

in comtroller take a object of the table let us say Image

table = Image.new
table.image = "image"
table.save()

Thanks
Ekta

Thanks.