You can find the "Alt codes" at this page:

http://www.angelfire.com/ak2/timothydrew/altkeys.html

As said, "e" can have both accents in Italian.
is obtained with Alt - 0232
is obtained with Alt - 0233

The best thing is to print a table and keep it ready on the (physical) desktop, the alt codes are very fast, faster than making all the copy-and-paste from another page, especially considering that after a while they can be learned by memory.