If you are thinking about installing the newest version of Google Chrome in Debian Lenny, don’t waste your time, you can’t (actually, you can but i don’t think you want to compile every package dependency).
The Google Chrome team is not supporting Debian Lenny and the latest package version supported is Google Chrome 12.
The package depends on other packages that are not in Debian Lenny anymore, there isn’t even a backport package for some of them. So, if you want this browser in the “super stable” Lenny version, you need to be satisfied with the version 12.
And if you really need the newest version, upgrade to Debian Squeeze. The installation in Squeeze is pretty straightforward, just install the .deb and resolve the dependencies:
dpkg -i google-chorme-latest-version.deb apt-get -f install
I couldn’t find older packages in the Google Chrome page, so here you have a link to the 12 version: