Prioritize investing in Finesse and Wits to improve their ranged damage and Critical Chance respectively. Similarly, a Ranger's attributes are quite easy to work out.
Rangers will want to deal as much damage as possible, so improving their critical hit rate is a great idea. While it may be tempting to pick an Elf for their thematic closeness with rangers in fantasy, being a Human will grant a nice bonus to Critical Chance.
The first choice a player must make when creating a character is picking a race, and each has different strengths.