luke@phage(0) $ find .
.
./.site.pp.swp
./site.pp
./test
./test/one.pp
./test/two.pp
[~/tmp/manifests]
luke@phage(0) $ cat site.pp 
import "test/*"

include testing

class base {
    notify { "this is base": }
}
[~/tmp/manifests]
luke@phage(0) $ cat test/one.pp 
# Testing

class testing inherits base {
    notify { "testing one": }
}
[~/tmp/manifests]
luke@phage(0) $ cat test/two.pp 
# Testing

class testing inherits base {
    notify { "testing two": }
}
[~/tmp/manifests]
luke@phage(0) $ puppet site.pp 
notice: this is base
notice: testing one
notice: testing two
[~/tmp/manifests]
luke@phage(0) $