There are 2 main commands I use daily to find files on your hard drive. The first is locate, and the second is find. man locate, and man find will tell you more about these commands.

Locate relies on a database of all the files on your hard drive. This database is normally created and maintained by cron scripts, if you run locate and it says something about your database isn’t updated run updatedb and wait for a long time. I often run updatedb & so it runs in the background so i can keep looking for the files i want manually. The basic way to use locate is locate word. This will search the locate database for “word”. A few quick notes, like most things on Linux the search term is case sensitive. So Word and word will match different patterns. Also, this will match words that contain your search pattern, so avoid short searches. If you’re looking for a bunch of files try piping your output to more or less.
locate word | less

Find all .mp3 files on your hard drive
locate .mp3 | less

Find your log files
locate .log | less

Locate is more useful if you don’t know which tree/directory the files you’re looking for are in. Also, locate -i will ignore the case of the searched term, so if you want to find all .mp3 or .MP3 or .Mp3 files
locate -i .mp3 | less

Now, find searches a given path, for differnet types of information.
It’s useful if you need to find changed files in a specific tree of your hard drive. It’s syntax is a little more confusing, and in my opinion non-intuitive. from man find we get it’s usage as
find [path...] [expression]

The most common way I use this is
find . -name “*word*”
where word is part of the filename I’m looking for
This finds all files in the current directory and below with word in their names.

But, you can do more than just simple word pattern matches
try these

Find all files in the current directory and below accessed within the last 60 minutes
find . -amin -60

Find all empty files in and below /home/me
find /home/me -empty

With these 2 find commands you should be able to find most things on your filesystems. Checkout the man pages, (man locate and man find) for more examples and full usage.

One last thing, if you’re always finding you need to updatedb then you’re linux box isn’t running updatedb from any cron script. Write one! Add it to your crontab.
I recommend making sure you don’t have an existing crontab as root.
crontab -l > /root/cron

edit /root/cron and add a line like this
0 0 * * * /usr/bin/updatedb >> /root/update.log 2>&1
make sure it’s all on one line
then run
crontab /root/cron
run crontab -l to check that you’ve installed roots new crontab file correctly
and now your update database should be rebuilt nightly