I actually had a point not too long ago where I went ape-shit going through wikipedia looking at all the different marvel and DC comics, heroes, universes, etc. It's insane how expansive it is
One series that interested me in particular was the Green Lantern. I've also heard good things about Spawn and Deadpool, and they both sound like my cup of tea.
I know I'm just echoing others here but the DC relaunch may be perfect for you. The idea behind it is specifically aimed at attracting new readers who feel it's too overwhelming to pick up comics. If you're looking into Green Lantern I'd recommend picking up the upcoming Green Lantern #1 and maybe Green Lantern Corps #1 or even Justice League #1. If you like Batman I'd say pick up Batman #1 when it hits stands because the writer on the book has been kicking serious ass with his last arc. The other cool thing is that if you're too far from a shop DC is also going digital for each of their books when the relaunch hits. They'll be online the same day they hit stores and get discounted after a couple of weeks.
I'm not a Spawn guy so I can't help you there, but if you want a modern Deadpool I'd probably stick with his main book. In the past few years Deadpool has kind blown up to Wolverine proportions, with something like 10 different series and mini series. Its calming down now and his current arc only has one more issue to go so issue #43 will be a new story and a jumping on point.
As for general things:
- If you find a book you like, check out the writer's other works. Its the fastest way to expand to other books.
- Ask the guy/girl at the counter for suggestions. They're the ones who know best on what's popular, and if you give them an idea of what you want to read they'll be able to point you in a good enough direction. Every comic shop is hurting a little these days and want people as return business. Its also possible they may have some sort of repeat customer program (both of mine do at least) where they'll knock off a couple of bucks for X amount of dollars spent.
- Mongo is right that it isn't a cheap hobby, but it also comes down to how much you read. If you're only reading 5 books that roughly should come out to $15 - $20 a month. I myself follow quite a few so I spend $35 or so a week; which is down from my old $45 or more a week. But there's always the option of picking up trade paperbacks which usually collect 4-6 issues for $15 - $20. The only downside is you'll alway be a few months behind. But going digital is looking like a godsend for me for titles I'm on the fence about.
- Comics come out every Wednesday and most site have their reviews up by the next day. Always check out more than one site though because sometimes you can come across a review that is particularly biased to particular writers; ign is a huge offender. Also browse the comment sections on reviews to see what the general public has to say, but no need to go nuts and read every single one.
Sheep Cannon: (noun) A cannon discreetly disguised as a harmless sheep.
Usage: See issue Deadpool #16: Assignment in Greece
I hate you Grant Morrison, your package, and everything about you.