This guide is only up to the Civil War arc.
Note: In no way are most of these intended as in depth reviews or judgement calls. They're just meant as a way of telling how much relevant Captain America content an issue has - with slight snark thrown in to keep me from getting bored.
0 stars = Captain America appears in no significant way in this Captain America story.
*= Cap appears in the story
**= Cap *and* a major comics character (Tony, Sharon, Bucky, Sam, Clint etc.) appear in the story in a significant way.
***= Cap has a particularly good plot OR Cap has significant personal interaction OR something of great fannish interest happens.
****= More than one of the above options
*****= The plot is significant to Cap's personal arc
Captain America issue 1 = ***
Steve and Sharon are decidedly off again. Steve gets snippy. Meanwhile the Red Skull has the Cosmic Cube and a dastardly plan. Steve is stressed because the Red Skull is on the loose. A mysterious man appears.
Captain America issue 2 = ***
Steve angsts. Who killed the Red Skull? Not him!
Captain America issue 3 = **
Steve angsts. Who killed the Red Skull?
Captain America issue 4 = **
Steve has hallucinatory flashbacks and gets beaten up by a guy in a black skull mask. Who kiled the Red Skull?
Captain America issue 5 = ****
Steve has major flashbacks full of important and interesting Bucky backstory! Also, the mysterious man is a Russian.
Captain America issue 6 = ***
Sharon is missing, steve visits the site of his "death" and hallucinates snatches of the fateful day. Also, Steve appears to randomly have a psychic connection to Sharon, which is not explored or explained.
Captain America issue 7 = 0 stars
A Captain America comic with no Captain America content! Very important if you're into Jack Monroe aka Nomad, though. Jack is dying horribly, trying to be heroic, and going literally insane while doing so.
Captain America issue 8 = *****
The mysterious man is a Russian agent called Winter Soldier and he's BRAINWASHED BUCKY!!!!
Captain America issue 9 = **
Filler. Steve and Sharon and Fury make an assault on the Russian base of Winter Soldier's controller Lukin
Captain America issue 10 = ****
In the House of M universe, Steve didn't end up frozen and separated from Bucky, and lived through the 20th century.
Captain America issue 11 = ****
Winter Soldier backstory-palooza! Where he was and how he got brainwashed. Steve angsts.
Captain America issue 12 = **
Steve angsts about Bucky, has a few flashbacks
Captain America issue 13 = ****
Sam (The Falcon) comforts and counsels Steve. Iron Man appears for some conversation and backup in a fight. Plot happens! Generally great!
Captain America issue 14 = ****
Steve fights Winter Soldier! Deus ex Machina time!
Captain America issue 15 = 0 stars
No Cap in a Captain America issue. All you get is the Red Skull's daughter Synthia being brainwashed and brutalized.
Captain America issue 16 = ***
Steve and Sharon are on again. They track Bucky to a small town that is secretly an AIM base.
Captain America issue 17 = ***
Steve and Sharon vs Crossbones and Sin in a small town that is secretly an AIM base.
Captain America issue 18 = **
Steve and Sharon go to London on the now-unbrainwashed Winter Soldier's trail and meet Union Jack and Lady Jacqueline (Spitfire). Bucky/Winter Soldier is there too, does a good deed, and plots.
Captain America issue 19 = **
The Red Skull is taking over Lukin's body. Steve, Sharon, Union Jack and Spitfire fight neo-Nazis in London, Winter Soldier lurks.
Captain America issue 20 = ***
The Red Skull is taking over Lukin's body. Steve, Sharon, Union Jack and Spitfire fight neo-Nazis in London, Winter Soldier lurks, Lady Jac and Steve bond and discuss Steve's relationship with Sharon.
Captain America issue 21 = ****
Steve and a now-unbrainwashed Bucky fight a giant Red Skull bot in London together, and bond for a couple minutes before Bucky vanishes. Steve feels hopeful.
CIVIL WAR HAPPENS
Here ends this guide, many other people have covered the territory of Civil War and what happens after.