How to use condor:
To get help with a command, do command_name -h
condor_submit: followed by your submission file, sends off your jobs (like qsub)
condor_q: tells you what is running (like qstat)
Some of your jobs may be held. This means that at least one of them had an error. Condor stops submitting them until you think the error is fixed. You can then start them up again (even the one(s) that failed) using condor_resume -username, substituting your condor username for username. It could be that only one node is having problems, so you can just resume and hope that they'll end up on other nodes. Better is to find the error, of course.
condor_status: tells you the status of nodes
condor_rm: followed by user name, removes that user's jobs (no, you can't delete someone else's). You can also specify individual job numbers or cluster numbers (a set of related jobs). See condor_rm -h for more options.
Error messages:
"About to exec /condor/condor-install/var/execute/dir_7640/condor_exec.exe" followed by "Create_Process: child failed with errno 2 (No such file or directory) before exec()": Probably means that something you're trying to run is not installed on that machine.