well, since you offered... ;) I've heard differing advice on using coffee grounds in gardens: some say you should and some say you shouldn't. Am I doing my garden a disservice dumping each day's pot of coffee grounds into the dirt? I'm trying to grow tomatos, peppers (jalapeno, bell and poblano), cilantro, beans, squash and zucchini.
Many people get confused about pH. Coffee grounds are acidic. But it will have negligable effect on soil pH. Something about buffering capacity (I'm sure I'll be corrected by someone). Same thing with pine needles. They are acidic but will not change soil pH.
They won't make much difference right away, but adding organic matter improves the soil over time.
When adding something, it adds more CEC attachment points, but also more cations and more hydrogen.
Within just the coffee grounds, many of the CEC points are occupied by hydrogen, so it is acidic. But when you compare the number of CEC points to that in the soil, the amount in your soil overwhelms. The good cations in your soil wont be affected much until you have enormous levels of coffee grounds (like >10% or something, I'd have to calculate it and I haven't).
And of course you can always just measure the pH and add cations which will displace the hydrogen (it will bond with the anion). Calcium is cheapest which is why people use agricultural lime. Dolomite will give you some magnesium which will probably produce healthier veggies. Potassium is important but too much will just bulk up the veggies rather than letting them develop more healthfully. Sodium is almost never useful.
Zucchini is easy and you'll be amazed how fast they grow. So is squash (same family).
Tomatoes, peppers and cilantro don't grow well where I live. They like the heat.
Therefore Zucchini grows as kelp, as usual, but beans just so-so. They will still yield but will not develop nodules.
You could find useful to rotate parcels and put the beans in the old soil, not in the freshly enriched this year.
In cold areas you can try rhubarb and horseradish (a wasabi substitute)
Horseradish grows like a weed here, rhubarb also does great, you are spot on with that advice.