Mike and Lori
It depends on what type of work one is looking for. workamper.com is a very popular source and I would bet it's how most RVers fiind a job. Their listings are extensive and one also gets a daily email with openings. They also cover pumpkin and christmas tree lots (notice there is frequently an RV parked behind the lot?). I used the site to get a stellar job for last summer. I let my membership lapse, however, since I am looking more towards primitive campgrounds. I used another source for the host job I have lined up for this summer. I lucked out and also have a job teaching silversmithing for a few weeks prior to host job. There must be gods.
Here's some other ideas and I can dig out others if I go through my laptop files:
Workamping at Lake Mead, NV. Callville Bay Marina & Resort 702-565-8958
Check into Southern Cross, gasline inspectors and Medora, ND, suppose to have a lot of seasonal jobs
Contact employers even if you don't find a help wanted advertisement.
Artspan – if you are an artist and sell your work > Artspan is the leader in artist websites and in search rankings by the top search engines. Artspan sites: low cost, high visibility, ease of site management. www.artspan.com
Many Alaskan public schools hire RVers to park on their property and watch it in the summers
California Land Management http://www.clm-services.com