Greek: An Intensive Course, 2nd Revised Edition https://www.amazon.com/dp/0823216632/ref=cm_sw_r_cp_api_i_tLcOFbC3BWVTA
That’s the book I used to study Greek. It’s a course in Ancient Greek and its very good, and with the help of a dictionary and some pointers here and there enables you to read the Bible just fine.
I very briefly flirted with the idea of studying Greek fifteen or so years ago. I ordered a copy of Greek: An Intensive Course, but the merchant could fill the order and cancelled it, so I gave up. It probably wouldn't have gone well; my record on actually learning languages is pretty poor.
The folks at /r/AncientGreek could probably give a much more in-depth answer for general strategies on this, but my personal recommendations would be:
Probably the most rigorous modernly-used text for learning Greek is Hansen and Quinn. It's great for developing grammatical skills, but kind of limited on vocabulary. (But by God by the end of it you will know how to say "Homer frees the slaves/sends gifts to his brothers/etc." in at least 50 different ways.)
Athenaze (followed by Athenaze II). I get the feeling these are kind of the Ecce Romani of Greek (that is, centered on a kind of contrived, silly family-centered plotline) but I really enjoyed that kind of simple constant when I was learning (what was to me) a very complicated language.
Morice's Stories in Attic Greek and Rouse's Greek Boy at Home! (You can find a sample for the printed edition of Rouse, which in my weakness I actually bought off of Amazon, here.) Very cute/interesting little stories that get progressively more difficult. Rouse has the added benefit of a Greek glossary in Greek, which (daunting though it sounds) is tremendously helpful in building vocabulary (and a lot closer to the system of how other, modern languages are taught).
Bookmark this site. Learn it, live it, love it. One classics degree and a year of grad school later, and Perseus is still my best friend. It's an online dictionary (from multiple sources) that also parses words for you! Be wary of using it as a crutch, but it's incredibly helpful even for most Byzantine texts. If you've got a smartphone, also check out Logeion - no parsing (yet), but still more dictionaries (very helpful when you're trying to find out what exactly a rare/Byzantine word might mean).
Good luck!
I used Greek: An Intensive Course by Hansen & Quinn to play catch-up before graduate school. The textbook is really useful for learning the grammar.
https://www.amazon.com/Greek-Intensive-Course-2nd-Revised/dp/0823216632
I posted a similar question yesterday but regarding study habits here Maybe it can help you too.
My only source has been the textbook by Hansen & Quinn (Amazon Link). It shows all the grammar and vocab in a very detailed and organized fashion. That said I am still a novice but I have heard that after the completion of H&Q you should have the proficiency to tackle the NT.
Hopefully that helps.
https://www.amazon.com/Greek-Intensive-Course-2nd-Revised/dp/0823216632 Read this, memorize the grammar, and work through the exercises. You’ll be off and running.
Greek: An Intensive Course. 2nd Revised Edition. Hardy Hansen / Gerald Quinn
https://www.amazon.com/gp/product/0823216632/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
If you attend a Bible college or seminary, you will know just enough Greek to fake it in the pulpit. You will be doing what my friends and I call "exegetical magic" and will dazzle people by saying, "Oh, that translation says 'run'? Well, Paul here actually uses the verb meaning to jog briskly."
If you really want to know Greek and be able to utilize it, pick up Hansen and Quinn's <em>Greek: An Intensive Course</em> and/or Mastronarde's <em>Introduction to Attic Greek</em> (if you're into linguistics).
For a real "nuts and bolts" approach, I would use Hanson and Quinn's "Greek: An Intensive Course". It's intense indeed, but it shows you everything behind the curtains since it is a grammar based approach. The are a lot of other books. Some like Athenaze try to use a more intuitive (and slower) approach, with a lot more vocab. I'm sure people here will have other suggestions, but I don't have experience with Reading Greek.