Can any B&N techie explain/help?
There are no B&N techies on these forums, just other customers and a forum administrator. If you want a B&N techie, you need to call Customer Service at 1-800-THE-BOOK (1-800-843-2665), option 2 for Digital Support.
Those two e-books are huge. Bleak House is 13MB, Vanity Fair is 22MB. Because of their size, those e-books are not available for delivery over 3G. See the availability notes on their pages (beneath Pub. Date): "Available for download via Wi-Fi".
I don't know anything about iPod Touch, so I don't know if there's a way to copy them from your PC onto the iPod. But you can't get them via 3G.