1. as for charging, charge at 0.5C (0.7-1C if you’re in hurry & your cells are of high quality). C refers to battery capacity, e.g. for 2600mAh battery 0.5C is 2600*0.5 = 1300mA.
2. conventional Li-Ion can be discharged down to 3.0V (under load), some cells permit lower voltages - e.g. 2.75V for most 2800/3000mAh 4.3/4.35V cells, and 2.5V for Panasonic NCR-series cells
3. Li-Ions are best stored at 40-60% SoC. For most cells this means open-circuit voltage of 3.7V, although it might differ - e.g. for LG 4.35V cells it’s 3.8V, and for Panasonic NCR cells it’s closer to 3.6V.
I agree w/ all Shadowww’s suggestions save the storage suggestion. I’ve had much better luck storing Li Ions charged up to 4.00-4.10VDC for long term [> 6 mo.] 3.7V is the lower end of the acceptable charge range and the few times I let cells rest for extended periods at that voltage some cells appeared to lose capacity. Since I don’t have a battery analyzer I’m relying on keeping track of run-times and cell voltage when I start charging. YMMV.