I have tried to find out how to edit the User Name field by going into admin>languages, admin>site settings>Users> profile fields and by clicking on the module and then selecting development but can not find out how to do it. I would like to do what I have listed below:

1. Change the help text from "Enter a username. It must be at least five characters long alphanumeric value" to something like "user names are your house numerical and street name with no spaces Example: if you live at 123 South Street your user name should be 123South"

2. I would like the default vale for the fallible filed to look something like this: User Name: [ Example: 123South ]

3. I would like to set up the User Name Validation to make it that if someone enters a username that is not three digits followed by text (no spaces) that it rejects it... Don't know where to start on this....

Any help, opinions or points in the right direction would be arrpicated!

Thank you Wes Tatters for the reply. The site I am working on is for only people within our home owners association ( easy way to explain it). The numerals throughout the area are only three digits. I would really like to let them use what ever they would like as a username, but this is how the board for the association would like it. So lets just say that the highest house numerical is 999 and the longest street name is Lakeshore if they were to enter 999Lakeshore would that code that you provided me with (thanks again) work? I have already edited the text if they enter it wrong with an explanation of how the format should be. I also edited the text on the registration page to advise them of how it should be.
Also, I would like to learn how to write the statement you provided, how can I go about doing that? Could you give me a bread down? Thanks so much for the help, you don't know how much I appreciate it!

The language is a special format called a Regular Expression or RegEx - it was a designed as a common language for searching / replacing and validating strings of text.   There are a number of different variants of the language - when used as a parameter in dnn - we are using the C# RegEx expression format.

^[0-9]{3}[A-Za-z]{3,9}$   would tell the system to require 3 numbers followed by 3 to 9 characters 

^ is a bounding marker - it says match the start of the string

% is a bounding marker as well - it says match the end of the string

Have a look at the microsoft page - http://msdn.microsoft.com/en-us/library/vstudio/28hw3sce(v=vs.100).aspx 
it has a lot of info on regex for asp.net and hence dnn.

And the code project at http://www.codeproject.com/Articles/939/An-Introduction-to-Regular-Expressions has a pretty good general overview.

ALSO You can find a lot of information about regex formats for common tasks at the reg library  - http://regexlib.com/