First install and/or update your Ruby and Capistrano (ruby -v, cap -V). Get to know the basics of Capistrano at http://www.capify.org/index.php/From_The_Beginning. I only describe here how to configure a basic recipe for CakePHP.

cd /your/project/root
mkdir config
capify .

This creates a few files. The important one which I'll explain how to configure for CakePHP is config/deploy.rb.

You must set a few configuration first :

set :application, "example.com"
set :repository,  "ssh://git@repo.repo.com/repo/repo.git"
set :branch, "master"
set :scm, :git 
set :deploy_to, "/home/user/domains/dev.#{application}"
set :deploy_via, :remote_cache # see http://www.capify.org/index.php/Understanding_Deployment_Strategies
# Configuration of you app path in the repo
set :cakephp_app_path, "public_html/app"
set :cakephp_core_path, "public_html/cake"
# Nice optional configurations
set :use_sudo, false # don't need this on most setup
set :keep_releases, 10  # only keep 10 version to save space
set :copy_exclude, [".git",".gitignore"] # or any match like [".svn","/documents-on-repo-but-dont-deploy"]

Your server(s) with SSH access :

# Roles
role :app, "user@exemple.com:12345"

Custom environments shortcut task (optional). It executes tasks and/or change configurations for a specific deploy. In my example, you can use "cap production deploy" which will deploy "production" branch on www and run CakePHP tests. You can also use "cap staging deploy" which will prompt for which branch to deploy and run cake tests. Default "cap deploy", on dev., does not run the tests (you may change all this, its just an example).

# Environements
task :production do
    set :deploy_to, "/home/user/domains/www.#{application}/"
    set :branch, "production"
    after "deploy:finalize_update", "deploy:cakephp:testsuite"
end

task :staging do
    set :deploy_to, "/home/user/domains/stating.#{application}/"
    set(:branch) { Capistrano::CLI.ui.ask("Branch to stage: ") }
    after "deploy:finalize_update", "deploy:cakephp:testsuite"
end

There is a default set of tasks executed on deploy, but we can add a few to the chain using before or after functions. I have set web:disable and web:enable which will create a temporary .capistrano-lock file for wich my CakePHP app will detect and display the maintenance page to users. Cleanup is to remove old releases (not executed by default as it would be an unexpected default behaviour).

# Custom events configuration
before "deploy:update", "deploy:web:disable"    
after "deploy:restart", "deploy:web:enable"
after "deploy:update", "deploy:cleanup" 

The tasks I configured :

# Custom deployment tasks
namespace :deploy do
        
    desc "This is here to overide the original :restart"
    task :restart, :roles => :app do
        # do nothing but overide the default because we don't need to restart a RoR app
    end
    
    task :finalize_update, :roles => :app do
        # link a custom configuration file for environment specifics
        run "ln -s #{deploy_to}/#{shared_dir}/bootstrap.remote.php #{release_path}/#{cakephp_app_path}/config/bootstrap.remote.php"
        # you may link here upload file folders if you have any, which should be placed in #{deploy_to}/#{shared_dir} which won't be overide on each deployment
        # overide the rest of the default method
    end
        
    namespace :web do
        
        desc "Lock the current access during deployment"
        task :disable, :roles => :app do
            run "touch #{current_release}/#{cakephp_app_path}/webroot/.capistrano-lock"
        end
        
        desc "Enable the current access after deployment"
        task :enable, :roles => :app do
            run "rm #{current_release}/#{cakephp_app_path}/webroot/.capistrano-lock"
        end
    
    end
    
    namespace :cakephp do
    
        desc "Verify CakePHP TestSuite pass"
        task :testsuite, :roles => :app do
            run "#{release_path}/#{cakephp_cake_path}/console/cake testsuite app all -app #{release_path}/#{cakephp_app_path}", :env => { :TERM => "linux" } do |channel, stream, data|
                if stream == :err then
                    error = CommandError.new("CakePHP TestSuite failed")
                    raise error
                else
                    puts data
                end
            end
        end
    
    end

end


Put all this code in your deploy.rb and you can now run "cap deploy:setup" once to init the Capistrano structure on the server.

Then point your document root to /home/user/www.exemple.com/current/app/webroot (which is an alias-symlink to /home/user/www.exemple.com/releases/20080819001122/app/webroot).