Fire Emblem/Band of Mercenaries

Red Villages
If you are playing this chapter in Normal mode, you will be forced to visit the two red-roofed villages on this map. The lower one allows you to recruit Wil, an Archer, and the upper one gives you 2,000 gold.

Armory
All weapons have a set number of uses before they break. It is always useful to have a backup weapon in case this happens, so that one of your units is not a sitting duck. The armory here allows you to purchase new weapons for your units, so make use of it and buy an Iron Lance for Florina. Save the rest of your money for the future, though.

Normal Mode
In Normal Mode you will be forced to visit the lower village to recruit Wil, an archer. After that, send Kent and Sain to defeat the single archer near you. The next turn, have Florina fly to the north village to receive 2,000 gold.

Then, send a unit of your choice (Kent, Sain, or Lyn) to the forest and have them wait there to draw in attackers. Be sure that they are equipped with Iron Swords before you end their turn. Then, move Wil behind that unit so that he can attack from afar. Once the enemies rushing your unit have been killed, send someone to the Armory to purchase an Iron Lance for Florina. If you have any weapons that have 15 or fewer uses left, consider purchasing a replacement for that weapon as well.

The boss, Migal, doesn't move, so you can weaken him with Wil, and then kill him with a lower level unit to help them level up (such as Florina, provided that a single hit from the Slim Lance is enough to kill him).

Hard Mode
In Hard Mode, make visiting the two villages your first priority. Then, dispatch the Archer with Kent and Sain. Florina should be able to take care of the Mercenary on her own, but if her HP is getting low, have her retreat to safety. Follow the same strategy from Normal Mode now, with positioning a Sword-wielding unit on the forest and Wil behind him or her. Once those units are cleared, purchase an Iron Lance for Florina and an Iron Sword for Sain. If any other weapons are running low, consider purchasing a replacement as well (you'll want to save Lyn's Mani Katti for the later chapters, so another Iron Sword might be a good buy for her).

The boss still doesn't move in Hard Mode, so defeat him however you think fit. The safest strategy is to weaken him from afar with Wil, and then close in with a unit that can kill him in one or two hits.