What is the best place to store static assets (files) in Rails ( pdf forms, xls files, etc)

Actually I just tested it by creating a folder in app/assets/files and sticking my xls files in there, and rake assets:precompile task just picked it up.

Also this needs to be added for Rails < 3.1:

    # Enable the asset pipeline
config.assets.enabled = true
config.assets.paths << "#{Rails.root}/app/assets/files"

The best place for items like this is still in the /public directory, remember to have your web server serve these assets directly also.

The assets directory is only needed if you want to take advantage of the asset pipeline. The asset pipeline handles things from compressing and compiling .coffee and .less or sass files to compressing your js and css into one file so your webserver only has to serve one file for each.

When you compile your assets with the rake task bundle exec rake assets:precompile they are moved to your public directory anyhow.