How to Insert, Delete and Reorder slides.
It is actually best to insert, delete and reorder slides from the 'Slide Sorter View'. To move to this view of your presentation, click on the 'Slide Sorter View' tool (bottom left of your PowerPoint screen, the one with four little squares).

Inserting a new slide
Simply click the 'New Slide' tool. This inserts a new slide immediately after the currently selected slide. So if you´ve just created your opening slide, the new slide will be Slide 2.
When you click the 'New Slide' tool, the New Slide
dialogue box appears, and you can choose the basic layout of your new slide just as you were able to do when you selected your title page slide.
Deleting a slide
Just select it and hit "Delete"! Some things come naturally, don´t they?
Reordering a slide
To reorder a slide, select it and drag it to its new position.
DON'T FORGET - use the UNDO button if you make a mistake.