A few questions about CI installation

[eluser]php dude[/eluser]
Hello everyone!

I'm in the course of learning CI and so far so good, but I have a few questions about CI installation:

1. How do I fix the 404 error when pointing my browser to the local copy of my website: ex: http://localhost/mywebsite ?
:: At this moment, only this would work: http://localhost/mywebsite/welcome (or whatever page I put there)
:: I added an index.php page inside my view directory but still no luck
:: I cannot create an Index class inside my controllers directory also, so I'm stuck...
:: Why isn't the framework providing such a file instead of the welcome one? Wouldn't this be a better example(starting point) for newcommers?

All I want is to be able to access the home page of my local copy of the website like this: http://localhost/mywebsite/ or http://localhost/mywebsite/index and not like this: http://localhost/mywebsite/welcome


Thank you in advance for any advices!