Well bash scripting isn't one of my strong points, going to have to do something about that ;D, but I'll give it a shot.
/usr/sbin/crond l1 >>/var/adm/cron 2>&1
Might as well start from the beginning:
This runs the the executable /usr/bin/crond
If /usr/bin/crond exits with a status of 1. A 1 exit status means error
Append, >> means append, to the file /var/adm/cron the output of standard output, 1 means standard output, and the output of standard error, 2 means standard error.
So all together we have, run /usr/sbin/crond and if it exits with an error append the standard output and standard error of /usr/sbin/crond to the file /var/adm/cron.
Do you follow or did I confuse you more?