Krias Hatorah

The old minhag was that only the Ba'al Segen (the Gabbai who decides who gets an Aliyoh), the Ba'al Koreh and the Oleh stood next to the Bimah, and this way there were three standing around the Sefer Torah, which is כנגד Moshe Aharon and Chur.
Today it is more common that 5 stand around the Bimah - the Ba'al Segen to the left, one of Chashuvei Hakohol to the right, the Ba'al Koreh the Oleh and the one who got an Aliyoh beforehand.
While reading the Haftoroh only the Oleh (who reads the Haftoroh himself) needs to stand by the Bimah.

Michael FRBSH

Both two minhogim are not very old as mentioned above. It does seem that generally in the more "Yekkish" shuls the Oleh usually goes to the left of the Ba'al Koreh.

Michael FRBSH