A quick search of the forum will reveal a wealth of information about the subjects you have raised. One of the most obvious being this one... http://coffeesnobs.com.au/YaBB.pl?num=1174699442
When youre starting off, dont try to over-complicate matters; just roast one bean type at a time until you believe youre getting the best flavour possible from that variety; keep good records of all roasts, including cupping impressions and then move on to another bean type.
Dont worry about blending any of them until such time as you fully appreciate the characteristics of each individual bean type and even then, dont blend prior to roasting rather, blend after the beans have adequate time to rest and degas. Only blend immediately prior to pulling a shot until such time as youve developed a ratio that tastes great to you and then youll have a handle on what works best for you.
Regarding degassing/resting..... It can vary quite a bit depending on bean variety, depth of roast, roasting method, ambient temperature, etc but the most important criteria is what it tastes like to you. The only way to learn is to cup your roasts right from the outset, just after roasting, every four hours thereafter and every day afterwards until the roast batch is fully consumed and keeping notes all the way through the exercise.
There really isnt any mandatory rule which states when the beans will be "right" for you as there are just way too many variables involved. There is the rule of 3s which, under ideal conditions, states that green beans can be stored for up to 3 years, roasted beans for up to 3 weeks and freshly ground coffee for a maximum of 3 minutes. I doubt if there would be too many of us here who would allow their freshly roasted beans to be hidden away for more than 4 weeks before cracking open the bag.
Even if you are using Zip-Lock 1-Way Valve bags, there is no guarantee at just how effective a seal the Zip-Lock on its own will provide. Ive got into the habit over the last 12 months or so of Impulse Sealing each bag immediately after filling the bag (with the beans still warm, about 40-45C). This seems to provide the best chance of stretching the "freshness" value of the beans and their flavour in the cup. But even using this procedure, the beans are all but consumed within a week of opening the bag so are never allowed to deteriorate to any significant degree.
The name of the game is experimentation Aaron as what might work for me or other CSers may not work for you. Its also the best way to learn as theres nothing like personal experience to cement in the methodologies that provide results.
Cheers mate, :)