For indexing, you can do a site: in the search engine to see what's been indexed. To look at a specific page, in addition to the site: operator, add inurl: and some words from the URL to help narrow down the results.
For caching, I use the Resurrect Pages extension for Firefox. Right click while you're in the page, and you can select one of several caching sites to see if that page is available. It's also handy for when you're getting a 404 on a page and want to see what was there.
According to the plugin page, you can use the following caching sites:
Searches through five big page cache/mirrors:
CoralCDN
Google Cache
Yahoo! Cache
The Internet Archive
MSN Cache
Gigablast
WebCite
The extension is available at https://addons.mozilla.org/en-us/firefox/addon/resurrect-pages/