I would check the legal notices in the local papers. The Burlington Free Press is the largest and the one that would probably be used by the IRS and local towns to notify of any impending tax sales or auctions. I would stay away from all the services out there that offer to supply you with lists. They are generally expensive and the lists that I have seen from other people have been out of date and/or irrelavant for the area that they were searching.
A few things to keep in mind:
1. Tax sales usually require a sizable cash deposit and have short terms for paying the balance (less than 30 days).
2. If the house is worth the money and if there is a mortgage on the property, expect to be bidding against the agent for whoever holds any current mortgages on the property. They need to protect their investment.
3. If it is a local tax sale, there is a year redemption period for Vermont taxes. So, it could be a year from the time of the auction until you are able to take possession, IF the current owner doesn't get themselves current.
4. Tax sales DO NOT cover the liens on the property. If you find a property you are interested in, check with the local town government for any liens. Those travel with the property, so you could end up having to pay someone else's mortgage, contractor bill or even the money for a paper route as they stay with the property, not the person.
Another thing to keep in mind, the homes listed at CitySideCorp.com for HUD are homes that had government guaranteed mortgages and are not IRS properties. If you are interested in any of the HUD homes, the link to the Vermont search side is: http://hud1.towerauction.net/VT.htm.
If you go that route, remember that you MUST put any offer on that property in through a registered HUD real estate agent. There is a list of them on the HUD site.
I linked the Legal Notices search at the Burlington Free Press below.
I hope that helps.