To manually enter a string (assuming your in Eclipse) double click the values/strings.xml file, when the new window opens at the bottom select "strings.xml". In here you can add your own strings in the following format: <string name="{a_name_here}">{you put the string's value in here}</string>
for example, I could store a URL for later use, it would look something like..
<?xml version="1.0" encoding="utf-8"?>
<resources>
<string name="app_url_1">http://google.com/</string>
</resource>
<resources>
<string name="app_url_1">http://google.com/</string>
</resource>
We can reference that string in our code like this:
String s = getString(R.string.app_url_1);