Tim,

I've got a house with vertical board and batten siding. I want to
build a deck, so I need to hang a ledger board.

A few options...

1. Remove the battens, tack up a temporary straight edge, and use use
circular saw to cut a kerf in the siding that you can slip the top of the
flashing into. The kerf should be cut at a 45 degree angle so that any
water that finds it's way into the kerf will drain back out and not into
the wall. Reapply the battens after the deck is finished.

2. Space the ledger board away from the wall using a stack of washers.
Bolts w/nuts would be best if you have access to the back side of the rim
joist (crawlspace or basement), but installation would be difficult and
definitely a two person job. Lag bolts would work almost as well, and are
much easier to install.

3. Add extra footings/posts and eliminate the ledger board entirely. Make
the deck self supporting so that no part of it actually touches the house.

Given a choice, I prefer to keep the deck isolated from the house (#3).
Otherwise I would probably go with option #2.

Anthony