Coffee grounds are great for improving soil tilth, drainage, constitution - but don't do much for fertility (adding essential nutrients). Freeze dried crystals would just dissolve - it is the non-solubles in the grounds that do the good. Egg shells are fine - chop them up - they break down slowly (we put the egg shells into our compost bin). For fertilizing naturally, you are looking to add N and P and K - nitrogen and potassium and phosphorous. Do some googling around - I tend to use the dilute blue stuff (Miracle Gro soluble balanced fertilizer), or a granular slow release (like Oscocote). For an organic alternative, the Tone series (tomato tone, plant tone, etc) are really good. But there is some expense for all of this. I am sure others here can add some good views. I am more of a variety and container gardening expert than culture expert.
As far as those crops - it depends where you live and the climate. Days to maturity are based on optimum growing conditions - and for things like broccoli and beets they like to start cool then get some warmth and sun. When the weather is cool, things grow very slowly. Days to maturity information on seed packets is really quite useless - for some plants it means days to maturity from good sized seedlings - for others from seed. Best thing to do is to look at a very informative seed catalog on line - like Johnny's Selected Seeds or Stokes - they provide really good cultural info.
Hope that helps a little! And enjoy gardening. It can be a most satisfying hobby - I've been an avid gardener for over 30 years....one thing to be aware of - every garden (each season) is an adventure and a learning experience. And for better or worse, it takes the mistakes to learn! Each year I have some things that surprise me in how well they do...and others that for whatever reason are the opposite - that's half the fun!
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