For your first question look at Excel online help:
Fill in a series  of numbers, dates, or other items
1. select  the first cell in the range  you want to fill, and then
enter the starting value for the series.
To increment the series by a specified amount, select the next cell in
the range and enter the next item in the series. The difference between
the two starting items determines the amount by which the series is
incremented.
2. Select the cell or cells that contain the starting values.

3. Drag the fill  handle over the range you want to fill.
To fill in increasing order, drag down or to the right.
To fill in decreasing order, drag up or to the left.