One of the GREAT things about Gmail is the search feature that is available. To do a search, simply type your search term (or email address) into the search bar at the top of the Gmail screen. Make sure you are not typing into the URL field (address bar) at the top of the screen.
However, sometimes when you search for an email, you may find that you get too many results and that you'd like to narrow your search a bit more. To do so, click on the down arrow to the right of the search bar. In the resulting window you can narrow your search in numerous ways including subject, attachments and even a date range. You can also eliminate certain words and/or email addresses as well.
By clicking the link at the bottom "Create filter with this search", you can quickly refer to this particular search later. In the resulting window you have several options including creating a label for any/all emails that may arrive in the future and you can have the message automatically archived. This means that it will skip your inbox and go to the label or newly created label automatically.