Showing only excerpt of articles or a selection of articles on home page

Dear Tom,

On my website http://www.csld.fr, I usually create long articles, which are perfect to be read in dedicated pages, but too long for the home page.
I'd like either to show only an excerpt of articles on home page, or to show only on home page articles that belong to my ''home"" category.

Note that I'd rather do so using the standard features of WP & GP, than introducing any specific php code, but OK with introducing some script/php/html code inside the articles.

Thank you for helping

Cheers
Damien