Perhaps the number one advanced find question is:

How to stop find from descending into subdirectories?
find command
Performing a non-recursive find in Unix
Use -prune with find command on AIX
Searching for files over 30 days old in current directory
disk space used for files with in a directory structure.
Question: non-recursive find syntax

Another important concept is using find in conjunction with xargs when dealing with a large number of files.
Too many files to list / remove
grep command-HELP?!
+ instead of ;

For more precise control over files found via a timestamp, use find in conjuction with touch as mentioned in:
files between any two given dates
no [find -mmin -1]
find command using -mmin param
a find script


And I thought that I'd link in other cool examples involving find...

The trouble with FIND .......
Cp All But Some Files, paramater for cp command?
/ is full

Finally, from the USENET Unix FAQS, see: Why doesn't find's "{}" symbol do what I want?