Interesting video here ('web cast' maybe? What's the difference?) about visualising data - focusing on tables, graphs and dashboards. If you don't know what a 'bullet graph', or a 'sparkline' is then this is for you. Most of it is non-product specific as well.
May sound a bit dry but this is one area of BI you can't ignore and can result in all of the behind-the-scenes effort going to waste.