Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
Basically this Ashe build is for straight up dps. You will be squishy, but the aim is to kill them before they have the chance. Ghost is used for escaping, or helping chase people down while using your Frost Shot. Volley and Frost Shot are prefered first spells, Don't use Frost Shot too much yet because the mana regen from runes hasnt kicked in yet, its mostly to get slow for your Volley.
Got bored, Ill edit some more!