I read a couple of books and lots of Web pages, but mostly I ask people on this thread and other plot holders. Then ignore the latter as they just tell me to cover everything in glyphospate, and build massive structures out of wood! No, they are actually v nice. Just obsessed with weedkiller.
I inherited a shed but it is v v broken, has not much of a roof and is very insecure. So I only leave chicken manure and stuff like that in there. But - I only live a few minutes walk away, and I only have 1 set of tools anyway, so schlepping them about is actually fine. Plus the spade belonged to my late dad, and id really hate to lose it. If I need to I can take my car there, eg if I have manure to take to plot. Also, much as I love it at the mo - and I really really do - I don't really know if the love will last, so I want to do it cheaply the 1st year. Hence no new shed, no new tools etc.
If I do still love it next year as I fully expect to, I think I will get one of those boxes instead of a shed, and leave a few bits up there. The only things I really use though are trowel, spade and trug, and a hand hoe thing. Plus I've used a rake a couple of times to spread mulches, also loppers and secateurs but I don't use them regularly. My soil is heavy clay so not really that rake-able yet. When I have stuff growing, I expect I'll need to use a longer hoe.
Maybe ask around and see if the other plot holders agree that there are no troubles with break-ins, and get a feel for what they do with their tools?