It should be no surprise that the first significant character in 1 Samuel is Samuel himself. Samuel was the last great judge of Israel and one of its first prophets. Samuel's birth (see 1:20) was an answer to the heartfelt prayers of his mother Hannah.
Saul was the first human king of Israel. Though he began his reign with humility, he soon became proud and deliberately disobeyed God. When God removed him form the throne, David became the second king of Israel. First Samuel tells of David's life before his reign began.
An additional character of note is Eli the priest who raised Samuel as a young child in the temple of God.
Among the important places mentioned in 1 Samuel are Ashdod, Gath, and Ekron. These Philistine cities had the misfortune of being hiding places for the ark of God when it was stolen from Israel. God wreaked havoc on each city as long as the ark was there. The Philistines finally returned the ark, and the men of Israel brought it to Kiriath Jearim, where it remained until David delivered it to Jerusalem in 2 Samuel 6:2-3.