At the risk of being a tad patronising 
bless you! The fact you're posting here suggests that your other half is v. lucky! I've done this twice with no success and am just waiting for an FET so I'll give it my best shot with the caveat that other women have different ways of coping and obviously very different experiences of the procedure.
- Could understand but didn't?
I knew both my cycles had failed before the 2ww. My body was doing all the usual PMT stuff. My OH and a friend urged me to 'keep positive' but that just made me feel pants. First time round especially, my OH was convinced it would work. I felt like I had to deal with my disappointment and I felt responsible for his. Next time round he was more open to both the possibilities of success and failure and that helped me.
- Had read up on but didn't bother?
I read Zita Jones's guide to IVF (and read out bits to OH). I'm a bit sceptical about self help guides but this one was useful. I learnt a lot about nutrition for example.
I also wish I'd known about/read up on DHEA.
- Had taken initiative on without waiting for you to prompt/do?
Help following the protocol. I'm in a scientific profession but the protocol I was given was, second time round particularly, really hard to follow. It helps to sanity check with someone else that you are doing the right thing. OH stepped up to the mark for the second round (short protocol) and helped me write a mail to the private consultant explaining what was wrong with the instructions (or lack of) and how stressed it had made me feel not having adequate guidance.
- Was better at doing?
- Had organised/thought of before it happened?
Can't think of anything specific - perhaps talk about what you will do in every eventuality and scope out all the options available. For example, during my second round I stumbled across information from my clinic about donor egg treatment abroad. It came as a relief and surprise that my OH would consider this and it makes me feel more relaxed as I know that there are other oprions out there. We also had a look in to adoption too.
- Had talked about before it happened
On the first round we had 3 embryos but only put 1 back as we were scared of twins (hollow laugh). We had a cursory conversation in the transfer room with the embryologist about what to do. Really we should have both talked to the consultant before hand.
On the physical and emotional stress - physically I didn't find it too bad. If your OH is concerned over injecting then she needn't be, it's very simple (think warm knife through butter). The retrieval was all fine too. Emotionally it's harder. It's a big emotional (and possibly financial) investment over a long time period with no guaranteed outcome. As a couple perhaps think about and agree who and what you want to tell people. Don't just think about this cycle - think about all eventualities. Having IVF is kind of exciting as suddenly there is an opportunity potentially opening up. In the first flush of optimism there can be a strong desire to share. People have different comfort levels in terms of sharing but think long term with this (will they still be helpful if you are several cycles in/considering donor eggs/considering adoption) and remember you can always tell someone but you can't untell them. Primarily, it should be a joint decision so something to talk about.
Good luck to you both!