How to add a text box and category select to front page?

I am looking to allow users, once logged in, to add new posts/articles by using the front page.

If the user is not logged in, they should receive a prompt to login in the space of the text box which appears when they are. It basically needs to be a mini version of what is usually achieved using the admin panel of wordpress.

They should be able to write the title, main body and choose the relevant category.

Any ideas?