The Vermont State Archives are...how shall I put this...a little quirky.
There is a bit of online content here, but the Vermont Archives website largely serves as a pointer system to find offsite records.
Vermont Genealogical Research page is a good example. Don't expect to find name look-ups here. Instead, you'll find instructions for requesting offline vital records, descriptions of naturalization records held by various courts, and fat pdf documents on where to find military records and microfilms.
There are two genealogical databases here, the Nye Index to Manuscript Vermont State Papers, and the Series Database which indexes the archives themselves, but these too are pointers to non-digital materials.
Actually, there's a page listing all available Vermont archival databases and here again...quirky. I mean, the Notary Public database....? The records go back to the 1990's, and include expired notaries.
The Vermont Maps database... a pointer system.
Perhaps the quirkiest item of all is the Historical Vermont Campaign Finance Database. This is a list of all Vermont campaigns from 1916 through 2008, and includes financial details of the candidates (but not of donors to the campaigns).
What's an archive without photos? There's the Online Vermont Photograph Collection; it, too, is quirky and -- it has to be said -- mildly annoying. This is a small collection, miniscule, actually, awkwardly arranged under headers like Agriculture Dept, and Houston Collection. But still, it's browseable.
There's also an ArcCat database at the University of Vermont, a catalog of archive collections throughout the state in museums and colleges and the like.
Over at the Vermont Historical Society, you'll find more of the same. Lots of web pages, lots of pointers, not all that much online material. The VHS Resources page describes indexes (pointers) to manuscripts and Civil War materials, along with a few online transcriptions of letters from the Civil War. Similarly, their Genealogy page includes indexes to a wide variety of offline family history materials.
However, there is a rather nice, timeline-oriented Freedom and Unity collection, with some beautiful images. There's also the Rugg Collection, a small set of drawings of historical Vermont.