Adding your presentation will be like adding your document. Using google docs just simply click file and then click download as. A list will come up. Click the option that says powerpoint. Again open your file and click file on the microsoft powerpoint window. Then click save as and from there save it to your desktop to make finding it easier
Just click upload and then click browse in your slide share account. Then find your presentation and click upload. The presentation will then show up. Last just copy the embedded code to the right of the power point.
Putting it on your site
Just click on widget in your tool bar. then go down to other. Select it and then paste your embedded power point. A box should show up and then just save and the box will appear as a power point!