The course I'm doing ('the thousand most common words in Dutch' - though I doubt this is true, since it contains words such as 'spark plug'!) is very good. If pronunciation were provided (from a native speaker) it might become one of the greats. Dutch isn't - unlike, for example, Italian - a language that is pronounced by English-speakers as it is written, so provision of the spoken word would be a massive boost. The convergence of visual and aural aspects would at the same time further strengthen vocab retention and speed of uptake.