Some common starter solutions:
a. Imanish combo stone, a one stone solution: http://www.chefknivestogo.com/imtwosi1kst.html
b. Arashiyama starter set, very popular due to high value for the money: http://www.chefknivestogo.com/4pcshstset.html
c. Bester/Suehiro Rika starter set, also very popular due to high value for the money: http://www.chefknivestogo.com/3pcstoneset.html
d. Bester/Suehiro Rika/Stone holder/flattening plate/etc starter set, pretty much anything you would need is included: http://www.chefknivestogo.com/knshcoset.html
To get going, at the minimum you need a stone in the 1-2k range, but this would be a very minimal setup.
The typical setup for maintaining established edges is a 1k stone, a 5-6k stone, a flattening plate (diamond abrasive), and perhaps some stopping materials. The 1k/5k progression will get you to a keener edge than factory. The diamond hone is used to maintain the stones' flatness. Strops are generally preferred over steels for truing the edge because the margin for error is considerably greater with a strop. It is actually very easy to do significant damage to an edge with a steel.
Lower grit stones, coarser stones, are used to repair damaged knives or alter the bevel angle or grind. For someone starting out, it is best to do these task, if needed, with the 1k stone. A 1k stone can do these task, but very slowly, and for a newbie it is better to make mistakes slowly
. Higher grit stones, finer grits, are nice to experiment with or for task specific needs, like straight razors. In kitchen applications grits higher than 6k can actually diminish performance on some products.