I used to live down that neck of the woods so would suggest you put either Salisbury or Warminster in a search engine to look for accomodation in that area. It really depends on what you're looking for, whether you'll have your own transport etc. If you are under your own power, there are bed and breakfast places all over the South Wiltshire area - the nearest large village to Stonehenge is called Amesbury and I know there are several good B&B's there. If you're looking for proper hotels then Salisbury would probably be your best bet.
Sorry I can't recommend a specific hotel but there may be others on here who could help!
You'll love Wiltshire - it's a really lovely county! If you're heading down that way, don't forget to check out the other 'historical' places in the area such as Avebury, Silbury Hill and Uffington White Horse - all very famous!!!!