Cron jobs need quiet operation; if a command generates output, you’ll get an email from cron with the command output. So if you want to fetch a file silently with wget or curl, use a command like this:
curl –silent –output output_filename http://example.com/urltofetch.html
wget –quiet –output-document output_filename http://example.com/urltofetch.html
There are shorter versions of these options, but using the verbose options will make code or cron jobs easier to understand if you come back to them

I picked up a good trick from Russ Taylor in grad school. He kept a “howto” directory, and any time he ended up doing a bit of research to find out how to do something, he’d document it in a tiny file in a howto directory. I picked up the habit, and in my personal howto directory at Google I now have 1750+ little files