Recommended PDF Translations:
Translation of the Quran by Shabbir Ahmad: Click here. (My personal favorite)
Translation of the Quran by the Monotheist Group: Click here.
Translation of the Quran by Mohammad Asad: Click here.
www.Quranix.net (5 great translations side by side)
www.Islamawakened.com (41 translations side by side)
www.Quran.com (Useful for finding references)
Corpus.quran.com (Concordance of the Quran)
Quran: An existential reading by Farouk Peru (A great book on the summaries of Quranic chapters)
Destiny Disrupted by Tamim Ansary
No God but God by Reza Aslan
Islam Without Extremes by Mustafa Akyol
The First Muslim by Lesley Hazleton
Revival & Reform in Islam by Fazlur Rehman
Muhammad by Karen Armstrong
Others authors to check out would be: Khaled Abou El Fadl, Omid Safi, Amina Wadud, Laleh Bakhtiar, Fatima Mernissi, & Asma Barlas.
Recommended Progressive Muslim Facebook Pages: