Resources
Textbooks:
Decker - Reading Koine Greek - This is the main textbook we will be following.
Croy - Primer of Biblical Greek - A good textbook in Biblical Greek. The explanations are short and to the point. A lot of exercises.
Hansen & Quinn - Greek An Intensive Course - A standard textbook in Classical Greek. Very in-depth grammar. Covers everything one should know.
David Alan Black - Learn to Read New Testament Greek - Another good textbook oriented toward New Testament Greek.
I can also recommend the textbook and the workbook by William Mounce. However, the electronic versions I have are not very good.
New Testament:
BibleHub - Interlinear. Clickable text on the website.
Blue Letter Bible - Interlinear. Clickable text on the website. Similar to BibleHub.
StepBible - Interlinear. Clickable text on the website. Allows you to pick English translations.
Scripture 4 all - Interlinear. Downloadable as PDF.
Nestle-Aland - Not Interlinear. Simple text on the website.
SBL Greek - Not Interlinear. Downloadable as PDF.
Uni Münster - Not Interlinear. Clickable text on the website. Not easy to use.
Old Testament:
Kata Biblion - Quasi-Interlinear. Clickable text on the website. Has English translation of words.
The list of online dictionaries can be found here.