Using the -text option will give you the full breadth of information.
openssl x509 -text -in cert.pem
Other options will provide more targeted sets of data.
# who issued the cert? openssl x509 -noout -in cert.pem -issuer # to whom was it issued? openssl x509 -noout -in cert.pem -subject # for what dates is it valid? openssl x509 -noout -in cert.pem -dates # the above, all at once openssl x509 -noout -in cert.pem -issuer -subject -dates # what is its hash value? openssl x509 -noout -in cert.pem -hash # what is its MD5 fingerprint? openssl x509 -noout -in cert.pem -fingerprint