First and foremost, all of the files needed reside inside the MAMP folder inside your applications folder. (this makes a breeze to remove, just relocate the MAMP folder.)

Secondly, all of those files are visible, by default, in the finder.

As for using the etc/hosts file to redirect to individual folders inside MAMP’s htdocs folder, there are two routs to go locally, MAMP (freeware) requires that you edit the files manually in the MAMP/etc/ folder, whereas MAMP-Pro (Shareware) uses a control pane in it’s interface.

MAMP-Pro also uses one of the free dynamic IP interfaces to publish dynamic domains which in turn to your internet IP, and then in MAMP, point to these new sub-folders.

In either version, if you only want to make the sites accessible on your intra-net, you can update the hosts files on the individual computers on the network, or if your router allows it, create host records on the network’s routing tables. (My Linksys allows for this as well as one of my client’s NetGear Router)

This simplifies the task of updating all the computers HOSTS files on varying systems and platforms and puts the routes in one place.

I would recommend though, one piece of software, for future installs:
MAMP (MacOS, Apache, MySQL, PHP) a complete software install and management package developed for fellow novices, for just this purpose.

The folks at http://www.mamp.info have done a superb job of implementing all of the tools you explain here, in one easy to install, easy to remove package.

The Freeware MAMP and the ShareWare Mamp-Pro both provide complete packages for Mac-philes who want to host demo (or full fledged) websites locally.

Some of the tips you provide here are also, very useful in a high end production environment available with Mamp Pro hosted on a MacOSX platform. I even use it to host some client sites locally, and with your tips, have been able to provide better services for my clients.

Thanks so much!
gracie