Everyone here has a write-up, drawn from the same records that explain the names while you read the text.
Saul
King of Israel, before the splitIsrael's first king, given when the people demanded one 'like the nations.' Tall and promising, Saul started well but unraveled, offering an unlawful sacrifice, sparing what God had devoted to destruction, and hunting David out of jealousy. Rejected by God through Samuel, he ended by consulting a medium and falling on his own sword at Gilboa.
1 Samuel 9-101 Samuel 151 Samuel 31Study → David
King of Israel, before the splitThe shepherd-poet who killed Goliath, outlasted Saul's jealousy, and united the tribes with Jerusalem as his capital. A man after God's own heart, yet his adultery with Bathsheba and its cover-up cost him dearly. God promised his throne would endure forever, the covenant the Messiah would fulfill.
1 Samuel 16-172 Samuel 5-72 Samuel 11-12Study → Samuel
Prophet, last of the judgesGiven to the tabernacle as a small boy after his mother's prayer, and called by name in the night. He judged Israel, anointed both Saul and David, and warned the nation plainly what a king would cost them before giving them one anyway.
1 Samuel 1-161 Samuel 8
Hannah
Mother of SamuelA woman who prayed for a son so intensely that the priest assumed she was drunk, then gave the child back to God's service when he was weaned. Her song of reversal, where the proud are brought down and the hungry filled, is closely echoed centuries later in Mary's Magnificat.
1 Samuel 1-2Luke 1:46-55
Jonathan
Prince of IsraelSaul's son and heir, and David's closest friend, who protected the man who would take his own throne. He died with his father and brothers at Gilboa, and David's lament for him is one of the great elegies in Scripture.
1 Samuel 141 Samuel 18-202 Samuel 1:17-27
Goliath
Philistine championThe giant of Gath who challenged Israel's army for forty days and was killed by a shepherd with a sling. The text is careful about his armor and his reach, which is what makes the choice of weapon the point.
1 Samuel 17
Abigail
Wife of DavidA woman of quick judgment who rode out with provisions to stop David from slaughtering her husband's household over an insult, and talked him down. When her husband Nabal died, David married her.
1 Samuel 25
Gad
David's seerCalled David's seer, he advised him during the years on the run and later brought him the three-fold choice of judgment after the census.
1 Samuel 22:52 Samuel 24:11-14
Phinehas
Two priests of this nameEleazar's son, who ended a plague at Peor by driving a spear through an Israelite man and a Midianite woman, and was granted a covenant of lasting priesthood. A second Phinehas, son of Eli, was a corrupt priest who died carrying the ark into battle.
Numbers 25:6-13Joshua 22:13-34Judges 20:28
Eli
Priest at ShilohThe priest who raised Samuel, and who failed to restrain his own sons when they stole from the offerings and abused the women serving at the entrance. Warned that his house would fall, he answers only that the LORD should do what seems good.
1 Samuel 2:12-361 Samuel 3:1-181 Samuel 4:12-22
Elkanah
Samuel's fatherA man of the hill country of Ephraim with two wives, Hannah and Peninnah, who went up yearly to Shiloh to worship. His question to his grieving wife, am I not better to you than ten sons, is either tender or tone-deaf depending on how you read it.
1 Samuel 1:1-81 Samuel 1:21-23
Kish
Saul's familySaul's father, of Benjamin, whose lost donkeys sent his son on the errand that ended with Samuel anointing him king. Abner, Saul's cousin and army commander, held the northern kingdom together for two years after Saul's death before being murdered by Joab.
1 Samuel 9:1-102 Samuel 2:8-92 Samuel 3:26-27
Achish
Philistine king of GathThe king David fled to twice while running from Saul. The first time David escaped by feigning madness, scratching at the doors and letting saliva run into his beard. The second time Achish gave him Ziklag and came to trust him completely, while David raided elsewhere and lied about where he had been.
1 Samuel 21:10-151 Samuel 27:1-121 Samuel 29:1-11
Jesse
David's fatherA Bethlehemite of Judah, Boaz's grandson, whose eight sons were paraded before Samuel until the youngest was fetched from the sheep. His eldest, Eliab, is the one Samuel assumed was the choice, and who later snaps at David for coming to the battle line.
1 Samuel 16:1-131 Samuel 17:28Isaiah 11:1-10
Nabal
The man who refused DavidA rich sheep owner at Carmel who insulted David's men after they had protected his shepherds, and whose wife Abigail intercepted David's raiding party with food and a speech that talked him out of a massacre. Nabal died ten days later.
1 Samuel 25:2-38
Zadok
The two chief priestsDavid's two priests. Abiathar had escaped the massacre at Nob and joined David in the wilderness, carrying the ephod. Zadok's line came from Eleazar. At Solomon's accession Abiathar backed Adonijah and Zadok backed Solomon, and Abiathar was removed.
1 Samuel 22:20-232 Samuel 15:24-291 Kings 2:26-27
Ahimelech
Priest at NobThe priest who gave David the consecrated bread and Goliath's sword, not knowing he was a fugitive. Doeg the Edomite reported it, and Saul had eighty-five priests killed along with the whole town. Only Abiathar escaped.
1 Samuel 21:1-91 Samuel 22:9-232 Samuel 8:17
Naboth
The vineyard ownerA man of Jezreel who refused to sell Ahab his ancestral vineyard, since the law treated family land as inalienable. Jezebel arranged false witnesses, had him stoned, and handed the land to her husband.
1 Kings 21:1-241 Samuel 8:14