The World's Classics "Selected Poetry" by John Milton is virtually a complete collection of his English poetry. The price is low, the font size is quite adequate, and best of all it offers extensive annotation, a real asset to most readers.
The annotation is located in an appendix rather than as footnotes on each page. I first read a page of poetry unaided, moved to the appendix to browse the appropriate "footnotes", and then returned to the page of poetry. This may sound awkward, but it worked well.
Unlike many collections, this edition contained all of Milton's English sonnets, several which I had not encountered before. The lengthy "Paradise Lost" is moderately abridged and a new reader might find this a good way to become acquainted with Milton's epic poem. But a better approach is to read the unabridged Norton edition of "Paradise Lost". Look at the various reader reviews and decide for yourself.
I particularly enjoyed Samson Agonistes, a rather long, but not difficult poem. I suggest first reading the Biblical story of Samson in Judges, Chapters 13-16, to better appreciate Milton's development of this classic story. The suffering of the blind Samson in captivity is poignant, particularly as Milton himself was blind and aging when he created this remarkable poetic story.