You can test if your resolver works on checking DNSSEC by resolving one of the next domains.
dig www.dnssec-failed.org @<resolver>
dig www.brokendnssec.net @<resolver>
To check if a domain has DNSSEC enabled, you can use the delv tool. This can give you more information.
delv <domain> @<nameserver>
An other way is using the dnsvis package. You can run this on your computer, or use the online version. There is also the DNSSEC analyser where you can see detailed information about you zone.