The most convenient edition is the version at Sacred Texts; I have linked to that below. You can also find the book at Project Gutenberg, Internet Archive, Hathi Trust, You can also get a free Kindle ebook in four parts: Part I - II - III - IV.
Book 2: Sabha Parva
Book 3: Vana Parva
Book 4: Virata Parva
Book 5: Udyoga Parva
Book 6: Bhishma Parva
Book 7: Drona Parva
Book 8: Karna Parva
Book 9: Shalya Parva
Book 10: Sauptika Parva
Book 11: Stri Parva
Book 12: Santi Parva
Book 13: Anusasana Parva
Book 14: Aswamedha Parva
Book 15: Asramavasika Parva
Book 16: Mausala Parva
Book 17: Mahaprasthanika Parva
Book 18: Svargarohanika Parva
