I think page speed is gaining in importance with search engines (and always important for users!) so I'm keen to ensure that all my sites are optimised for speed.
There's a few new tools around (e.g. Google's page speed analyzer) that help to identify potential issues, but I've been unable to find any clear direction on how to resolve certain issues and what is considered best practice.
Firstly the 'Leverage browser caching' recommendation from Google's page speed analyzer - it's easy enough to set this up on pages, but how is caching achieved for image files?
Also with regards to setting an expiration date Google recommends "Specify an expiration at least one month in the future for resources that should be cached, and an expiration in the past for resources that should not be cached".
Historically many people prevented caching:
<meta http-equiv="Pragma" content="no-cache" />
<meta http-equiv="Cache-Control" content="no-cache, must-revalidate" />
<meta http-equiv="Expires" content="-1" />
to force SE's to download a fresh copy of the page, but is this bad practice now, will it slow page load times?
If caching is not prevented what should the expiry be set to for important pages such as the homepage which should be cached, but will change on a weekly basis?
Would be most grateful for some guidance on these issues.