I've been to several foreclosure auctions in Colorado, so I have a little experience. It seems you have some idea what kind of sale it is and its legalities, but I think you should be very cautious and research it extensively. Why is it being auctioned, foreclosure or tax sale? What would you be buying if you bid on it? When would you have clear title to it if you were the successful bidder? What, if any, redemption rights do the owners or junior liens have and how long do those rights last? What happens to your investment if the owner or a junior lienor redeems? Are there any superior or prior liens that you would take the property subject to (watch out for federal tax liens)? Is the home occupied?
I knew the foreclosure law when I was bidding on them here. I would do a title search to verify that there were no prior or superior liens on the property and that it was the first mortgage foreclosing. I would try to inspect the property, if possible. I would also research to see that the foreclosure was procedurally sound and likely would not be undone because of some mistake by the bank or their attorney.