New to CI (be kind)

[eluser]ShoKatoo[/eluser]
Simple...
Open ./system/application/config/autoload.php and scroll down to

Code:

$autoload['helper'] = array();

Now set this to

Code:

$autoload['helper'] = array('url');

This is quite self explanatory: will load the url helper that will give you access to the base_url() function.
As for the following question... I don't quite get what are you trying to say... please give some more info...

Have phun!