The Torah portion is Ha'azinu, Deuteronomy 32:1-32:52.
The haftarah is for Shabbat Shuvah, Hosea 14:2-10, Micah 7:18-20, Joel 2:15-27. The Sabbath of Return, between Rosh Hashanah and Yom Kippur, we read several short passages about returning to G-d after sin and being forgiven. The Hosea passage begins "Shuva Yisrael!" (Return, Israel!) and the Micah passage contains "Yashuv y'rachameinu" (He will take us back in love). The Joel passage talks about blowing a shofar (a Rosh Hashanah tradition) and solemnizing a fast (a Yom Kippur tradition). There is some variation in exactly what verses from Joel different synagogues use.
In synagogues using the Sephardic tradition, the Haftarah is Hosea 14:2-10, Micah 7:18-20.