Hi,
Most all seeds can be stored in a cool dry place just fine. Freezing is recommended for long term storage. There are certain things you must do for freezing so I don't recommend it if you are saving seeds to trade or if you plan on re planting you seeds in the next few years.
A few seeds need to be sown immediately or stored with moisture which I think you might vaguely remember reading somewhere and have confused for cold storage. Most of those seeds are spring woodland plants like hellebore or dicentra. Also some fruit seeds need moisture to be viable.
In general, a cool dark dry spot works just fine : )
Remy

Thanks!