How do you Read SharePoint Lists Programmatically?

You have several options both of which are going to require further research on your part they are:

1. Use the SharePoint object model (Microsoft.Sharepoint.dll), you must be on a PC within the SharePoint farm.
2. Use the SharePoint web services which can be found at SiteURL/_vti_bin/ you might want to start with Lists.asmx and work from there.

You are going to need some further research as I have said, but remember GIYF.

I would really encourage everyone on this topic to have a look at the ado.net driver for sharepoint from bendsoft.com. It is free for developers to use and allows you to query sharepoint information using standard sql syntax and takes care of all sorts of conversion for you.

Dim conn As New SharePointConnection("Server=mysharepointserver.com;Database=sitepath;User=spuser;Password=******;")
conn.Open()
Dim cmd As New SharePointCommand("UPDATE Employees SET Salary = 3250.50 WHERE Name = 'Steve Watson'", conn)
cmd.ExecuteNonQuery()