Are your staff are turning off e-learning? Read Paul Allman's advice for creating engaging CBT.
There are lots of things you could do to make computer based training (CBT) more interesting, but before you hurtle off and create wonderful graphics, animations, audio, interactions etc, ask yourself why?
Why are you doing this? Why do people find it dull? Is it because it is an online book? Or is it because the content is not suited to e-learning? Or is it that you are concerned about take up/drop out rates - in which case it may be you need internal PR & marketing?
You then also have to re-confirm the purpose of the CBT as this will affect the methods you choose to create it. For example if it is to 'teach' a new subject then you can consider using media that stimulates the three principle senses - audio, visual and interactive stimulus. Remember also that you need to consider technical and usability limitations before you do this. Alternatively, if it is as a reference point then too much multimedia may actually be an issue for users.
If you have done all this and you still feel that you need to make it more exciting then look at audio, strong visuals and interactions and limit the volume of text on a page wherever possible. Also consider using a good learning designer to review the content with you and possibly even write the new version.
Finally, bear in mind that all new e-learning content should be accessibility compliant to meet the needs of the Disability Discrimination Act.