Hi,
In addition to the techniques described in the other replies, there are
shortcut keys for accent marks that you can press before you type a letter.
If the accent-letter combination is supported, the accent will be added to
the letter.
For example, if you press Ctrl+' (Ctrl together with apostrophe) before
pressing e, é will appear.
If you press Ctrl+' (Ctrl together with grave) before pressing e, è will
appear.
Pressing Ctrl+: and then o produces ö.
Pressing Ctrl+^ and then o produces ô.
Pressing Ctrl+~ and then o produces õ.
Pressing Ctrl+, and then c produces ç.
Pressing Ctrl+/ and then o produces ø.
Pressing Ctrl+@ and then a produces å.
In all of these cases, you can press many other letters instead of the
letter that I gave in the example. These shortcut keys work for any supported
combination or an accent mark and a letter.