Since there is no Rick Steves Israel what is the next most helpful guidebook that travelers have found useful?
You can do some research yourself by going to GOOGLE or AMAZON or both and doing a search "Israel guidebooks". You then only have to decide which ones you want to buy. There are more than you have money for, I think. We mostly use Rough Guides and/or Lonely Planet Guides but when you get into that part of the world there are others to consider that I know nothing about.
I toured Israel twice and found Fodor's to be helpful. Will you be travelling independently or touring with a group?
When viewing books on Amazon, one option you can sort by is publication date, to get the freshest edition, including some new releases that might be coming soon.
We will be traveling independently, two nights in Tel Aviv, 5 nights in Jerusalem so hopefully time for one or two side trips from there. I purchased the Eyewitness Top Ten pocket guide to take with me but I am finding it less helpful for pre trip planning. I already have accommodations so I don't need that info but I do need a good guide to help me plan the basics, traveling between the cities, walking tours, historic site info, etc. I just really like the way Rick Steve's guides give you this info and obviously have become over dependent on him! ;)
You won't find something like the detailed instructions of a Rick Steves guidebook, for Israel.
Fodors or the other guidebooks are out there.
I recommend that you also get DK Jerusalem & The Holy Land, a good book with more illustrations/photos/explanations--it's not going to give you a Rick Steves approach or current prices like Rick's Europe guidebooks do. But well worth it for the illustrations alone.
Some of the biggest sights are in Jerusalem. 5 nights gives you only 4 full days there. I'd do only 1 full day in Tel Aviv (nothing sight-wise compared to Jerusalem or the Galilee) and shift any saved days from that to give you more nights in Jerusalem. Jerusalem is where the big sights are, a fascinating city with major sights of 3 of the major religions there.
With only 5 nights/4 days in Jerusalem, if you do too many day trips from Jerusalem, you will cut yourself short in Jerusalem itself.
If you have a particular interest in Christian-related sights (obviously, much of Israel is Jewish and Muslim religious sights), you want to focus on Jerusalem and the general area that could be described as The Galilee. As you probably know, The Galilee area is where Jesus spent most of his life and is where most of the sights associated with Him are (except for the earliest days and the last days, which are in or near Jerusalem.)
Bethlehem is an easy day trip from Jerusalem.
Masada is a full day trip from Jerusalem, but in the old days was done by going with a tour with an armed guard. I don't know about the security precautions now.