There is not much more I can add to the reviews already posted here. Jelling is a small village and the mounds sit right in its centre. In between the two mounds are a church and the two stones. The church unfortunately was closed for a funeral so 10 minutes after arriving I had climbed the two mounds and looked at the stones and was left wondering what else I could do. Fortunately the free museum was open, and this was superb. It really explained the significance of the site, and also helped decipher the stones for me. There were castings of the stones that were painted in vivid colours, these helped reveal the details of the engravings and also highlight the narrative of the text. Without the museum this would have been a slightly dull site to visit, however the museum did a great job of explaining the significance of the monuments.

I managed to visit this site as a day trip from London, thanks mostly to Jelling's proximity to Billund Airport. From the airport you can catch a bus to either Vejle (largish town with some nice shops) or Give (small village with a lovely church and great bakery) and from both of these it is one stop on the train to Jelling. Jelling itself is little more than a village, however it does have a little brewery and you can sample their very impressive output at the museum café. In Billund I also managed to get into Legoland, I had always wanted to go there when I was a kid, and it certainly didn't disappoint, it was superb. It is free for the last two hours of the day, which was a great way to end the day trip.

As said by the other posters here, Jelling is not the most astounding of sites to visit as the monuments are rather small, however the significance is well illustrated by the on site museum making this an interesting place to visit for a few hours.