Comic Books have been published for close to 100 years. Marvel and DC are the big ones that almost everyone knows but many independent publishers like Image Comics have made a mark on the industry. Even if you don't know anything about comics, you've undoubtably heard of Superman, Batman & Spiderman.
The most common category is the Super-Hero category. Other categories include manga, science fiction, action/adventure, horror, humor, romance, war, adult and so many more.
Comics are broken into 4 eras based on when they were published.
1938 – 1956
This is the beginning of what we consider "comic books". Superhero books were just starting to take off and included the first appearances of Superman, Batman, Captain America, The Human Torch, The Sub-Mariner, The Flash, Green Lantern and Wonder Woman. Besides the super-heroes, most of the other books were either Western, War or Detective themed.
1956 – 1970
Most consider the Silver Age to be the epitome of comics. Superman and Batman ruled the Golden Age but it wasn't until Stan Lee and Marvel (formerly Atlas) changed the game. Storylines from Amazing Spiderman, Fantastic Four, Captain America, Iron Man, X-Men and so many other classics kept kids coming back issue after issue.
1970 – 1985
Marvel & DC really own the industry. Marvel sees huge success with Wolverine, Ghost Rider & Punisher. DC continues to sell massive amounts of Batman and Superman. Many books took focus on social issues like Drug Use or Racism.
1985 – Present Day
Marvel & DC continue their reign. Image Comics competes for a decent share of the market. A few Independent publishers see mild success like Valiant & Dark Horse. Marvel movies now owned by Disney propel the industry into uncharted territory. Arguably, comic book collecting is the most popular it's ever been.
Condition is everything. Some Near Mint books have sold for hundreds of thousands of dollars. But it's not just the first appearance of Superman or Spiderman that can make you super rich. There are literally dozens of titles that have immensely appreciated in value over the last decade. And here's some good news – for many Silver & Golden Age key books, the condition can be absolutely horrible and still worth decent money. The reason for this is because there are limited amounts of these books left in the world and too many people who want them.
9.8 - 10.0
A perfect book. Older books rarely attain this grade. Values skyrocket in this condition.
9.2 - 9.6
A book that at first glance appears perfect but upon closer inspection there are minor imperfections. Older books in this condition are worth a pretty penny!
7.5 - 9.0
A book in excellent condition. Wear is easily visible but minor. Older books in this condition and above are very collectible.
5.5 - 6.0
A Mid-Grade Book. Presents very well with bright colors. Corners could be rounded. Anything here and below could be referred to as a "Readers Copy"
3.5 - 5.0
Moderate wear. Small tears, folds, browning, stains, etc
Majority of Silver Age books usually fall within this range due to poor storage and age.
1.8 - 3.0 Grade
Books is complete. Folds, creases and very small tears are acceptable. Low Grade books but certain titles are worth money.
1.0 - 1.5 Grade
Has all the pages and at least most of the cover but coupons may be cut out. There may be writing on the cover or inside. Book is possibly falling apart due to age. Book has seen better days.
Only Major Key Issues have value with this low of a grade.