Warlords are great. Typically you want to get into the thick of things and mix things up in melee. (You can go archer, but it isn't the best class for it.) If you want some awesome suggestions on powers and things, I would be remiss if I did not refer you to the D&D Char Op Warlord page. The folks who put these together have a lot of great ideas and even cover some basic tactics.
You specialize in moving your allies around the battlefield (Wolf Pack Tactics) and giving your striker and defender extra attacks (Commander's Strike). For the defender, it's more marks; for your striker, it's more opportunities to do major damage.
Warlord's Favor is useful as a power bonus. At this level, a +2 (to hit and damage I believe) is awful nice to have: it's an extra 10% chance to hit and extra damage to boot. That's very nice.
Hold the Line is essentially a debuff: by reducing your enemies' chance to hit by 10% (if they target AC) you are reducing the average damage they are able to put out. It's a bit suboptimal, but if your group stays in a tight group it can be useful.
A +2 bonus on encounters in early levels is quite useful. Anything more and you have to take a disadvantage. (Not your thing; taking penalties is more of a Bravura Warlord's niche).