Leverage Browser Caching to speed-up page?

Hi All,

I just uploaded a new theme to my site and I’m having trouble with my page-speeds. Part of my issues are related to pictures, but I’m also getting the following flag from Google:

Leverage browser caching
Setting an expiry date or a maximum age in the HTTP headers for static resources instructs the browser to load previously downloaded resources from local disk rather than over the network.

Apparently none of the static pics on my site have an expiry date. Any clue how I would do this?

I found the following:

But I am worried about any interactions this might have w/ Varnish Cache.

Tips, ideas?

Just to let everyone know. I added the code from the following link and it did help my pagespeeds by solving browser caching:

Hope this helps other people facing the same Google pagespeed flag. So far no negative interaction w/ my Varnish Cache.