The more people involved, the greater the glory of the Mitzvah: Menachot 63b-64a, 65a
On Shabbat, it is better to do one forbidden form of work to a larger extent, and minimize other ones, instead of doing some of many forms: Menachot 63b
The Grain
Whether the grain must be planted specifically for this Mitzvah: Makkot 8b
Source for using barley for the Omer: Menachot 68b
The only other flour offering which is barley is that of the Sotah, but that one is less refined: Sotah 14a
A messenger of the Court would bundle the sheaves, still connected to the ground, before the Holiday: Menachot 65a
Brought from near to Jerusalem, but default is anywhere: Menachot 64b
The nearby cities would come in for the harvesting: Menachot 65a
The Grain should be "Karmel" - soft and full: Menachot 64b, 66b
[Not] Brought from the valleys and irrigated fields, which produced poorer quality grain: Pesachim 11a, Menachot 68a
Soaked in water and drained, without fear that it may become leavened during the time used for the process: Pesachim 36a