Trying to get pre-foreclosures to wholesale...

[Tiese C.]

Help,
I have found 3 pre-foreclosures that I would like to wholesale. Okay, here's the scenario.
The first one, original principal amount owed $33,000 recorded in the city records 7/21/04. The city assessed it at $397,300. I went to the property and it appears to be abandoned. The auction is 7/21/08. I don't know if there is a second trust or any liens on any of these properties.

The second property is a trustee sale, $61,125 recorded 9/30/91. The city assessed it at $164,800. The homeowners were there last night, but b/c it was 8:30 pm, I thought it was too late to knock on their door. The auction is 7/29/08.

And finally, the last property is $48,994.84 recorded 10/27/05. City assessed at $217,798. Homewoner was home last night, but felt, again, it was too late to knock on their door. Auction is 7/23/08.

All of these homes are beautiful, in family oriented neighborhoods. Middle class. My question is: HELP!!! I want to wholesale these, but how can I find out if there any liens on the property or if there are any other trusts? Also, is 8:30 pm too late to knock on a homeowner's door?

Is there anything that I should look out for?

Any advice/suggestions...I'd truly appreciate it. I pray that one of these could be my first transaction.

Thank you,