You need to localize both the database and application.  You can download the Enterprise localization tool kit from the link below and use the second link to localize the application in Visual Studio .NET.   A quick trick put XML and others in notepad and save the file as Unicode.  Try the links below to get started. I am assuming you know NVarchar and NChar are 4000 and NText is 2gigs.   Hope this helps.

http://www.microsoft.com/downloads/details.aspx?FamilyID=6b6fb09f-f25c-48e9-9e26-b55144600da1&DisplayLang=en

http://www.aspnetresources.com/blog/unicode_in_vsnet.aspx

Kind regards,

Gift Peddie