The canonical texts of Islamic scripture are the Qur’an and the
Al-Sihah al-Sittah (six canonical Hadith collections).
Ibn Ishaq’s Sira and Tarikh Al-Tabari are not Islamic scripture, but secular works. I don’t think they can be found online anywhere, (for one thing Al-Tabari’s work is over 10,000 pages long and Ibn Ishaq’s work has been lost since the Mongols sacked Baghdad). They’re not the most authentic of sources, so I’d advise you to take anything you find quoted from them with a grain of salt.
Al-Sihah al-Sittah consists of Sahih Bukhari (online
HERE), Sahih Muslim (online
HERE), Sunan An-Nasa’i, Sunan Abu Dawud, Sunan Al-Tirmidhi, and Sunan Ibn Majah. The two most famous and authentic Hadith collections which you’ll find quoted by Muslims most often are Sahih Bukhari and Sahih Muslim, ‘Sahih’ here means sound or authentic, and Bukhari and Muslim are the names of the scholars who compiled them. The ‘Sunan’ collections are those which focus solely on documenting the Sunnah in a coherant fashion, whereas the Sahih collections record every Hadith deemed to be authentic beyond any doubt regardless of its subject. These four Sunan collections are listed as canonical because they’re by far the best works of their kind, however there are some Hadith in them which later scholars have deemed to be incorrect, so that’s why they’re not on the same level as the Sahih collections.
Also there are other Hadith collections not considered canonical, but still reputable, it’s important to remember that just because a Hadith collection isn’t canonical, that doesn’t mean there aren’t any authentic Hadith in it. The Imams of the four
madhabs, or schools of thought, for example all collected Hadith, so we have Al-Musnad by Imam Hanbali and Al-Muwatta by Imam Malik. You’ll see that Malik’s Muwatta is included in the USC/MSA website’s Hadith database, that is because although it is not canonical and Imam Malik was not a scholar of Hadith, but a scholar of Fiqh (jurisprudence), his collection is still as well put together as the canonical ones.
There are other minor collections too, but these are easily enough anyone would need to know about except those looking for a scholarship in the subject.
