In PHP you can do something like this:
echo date("l jS F,Y", strtotime($date_field_from_db));
The date manual is very useful for this.
Searching in a query against a date is like bradgrafelman mentioned. You can use mathematical operators on it and compare it to a date string (as long as it's in the right format yyyy-mm-dd) with things like =,< & >.
There are also times when you can treat the date like a string and use string operators on it in SQL, but that might be a bit beyond what you need right now.