My last attempt to answer those questions resulted in a book....
http://www.amazon.com/gp/product/1439223084/ref=cm_pdp_arms_dp_1
These are not quickly answered and I still find myself discovering things that cause me to re-evaluate views on various staves.
Basic summaries are possible, however:
One can use the Runes for divination and magic. Since this is a divination forum, and since one should learn to read before one tries to write, I will limit my answer to this aspect.
The probable historical methodology (from Tacitus) goes something like this:
1) Get a branch from a fruit-bearing tree, carve lots from it.
2) Mark each lot with a symbol.
3) Caste them onto a white cloth
4) Looking to heaven, select three lots then look at them and interpret them.
5) If the answer is unfavorable, accept it, but if it is favorable, follow up by asking sacred unridden horses, or observing the flight of birds.
6) Burn the lots after use.
There is no discussion what the three lots stood for. One possibility is past-present-future. Another possibility is king, warrior, and producer. I usually combine these into a 5-lot spread.
Modern practitioners rarely make a set of lots for each inquiry.
Aside from my book (referenced above), I would recommend "Rudiments of Runelore" by Stephen Pollington as a good place to start.
Also a few works by Edred Thorsson ("At the Well of Wyrd" and "Runesong" are probably the best for beginners), and a few others are also good.