More classes into one package or

hi to all!
i got flash cs3 some days ago, so i’m really new to actionscript 3. seems powerfull and i’m willing to dive into it.

now, the first obstacle that i cannot pass (i googled it and searched in this forum) is: can i have more classes in one package? if not, where can i put the file secondClassName.as and how to call it in order to be able to include it from baseClassName.as?
thanks in advance.