Reddit mentions of The Real Christmas Book: C Edition Includes Lyrics!

The overall lead sheet is from The Real Christmas Book.

The arrangement I created this morning was:

• Ballad/semi-rubato intro over first 8 bars
  
• Walking bass and melody once through the chart
  
• Solo
  
• Start referencing melody the last 8 bars
  
• Transition to ballad/semi-rubato for the last 4 bars.
  
• End a half step up from root (F#maj7) and then resolve to Fmaj7#11.

>Since I'm really new to jazz in general, I am not good enough to substitute chords on my own or come up with my own jazzy fills and lines.

This is usually my suggestion, but barring that, I'd go with /u/JacksonParodi's recommendation. The Real Christmas Book isn't my favorite, but it's probably the closest. The Ultimate Christmas Fakebook is another I like, though most of the chords are more traditional and you'd have to jazz them up yourself.

If you really want to get into jazzier playing you'll have to slowly invest in the chord knowledge though. It's especially crucial on accordion since there is no maj9 button and common things like 7#5 are physically impossible to play with the left hand alone. You'll need to know how to build these chords so that you can either combine basses in the left or supplement appropriately with the right to get the chord quality you're after.

Lead sheets are wonderful, but they require this bit of knowledge. Unfortunately, I'm not aware specifically of any songbooks with standard accordion notation that cover jazzy Christmas tunes (though I have some that are jazzy tunes in general). Lead sheets are pretty much always going to be your best bet and barring that, reading piano music and being able to adapt it (once again, through some chord knowledge) to accordion is the next best option. There are a ton of jazzy Christmas books for piano (and just music resources in general for piano as opposed to accordion). On the bright side, usually when something is arranged in a jazz style, they provide chords symbols over the top so that essentially turns it into a very fleshed out lead sheet. Books like this one are a good example.

how about the christmas fakebook? or another book of sheet.