Try Filet crochet. Filet crochet can be used to make any pattern at all by graphing it out first. Filet crochet has traditionally been used to make words and phrases.
You can find instructions on line or in your local craft store. On line, enter "monogram crochet". There are instructions how to crochet each letter in the alphabet.
Do a search for "ehow" in yahoo it will lead you to the "ehow" website. There is a story there titled "How to Crochet Alphabet Letters" by Rena Rossner.
If you do a net search ont thes you will be ab;e top find a lot of different books that you can buy that will show you a ton of different ways to make the letters.
There are several places on the internet you can use for crocheting letter and numbers. You can go to a search engine website and type in "crochet letters".