For intermediate to longer term storage, you can put dry yeast and LME in the fridge, hops in the freezer, DME & grains in a cool/dry place.
With dry yeast strains, you generally have the option to rehydrate or sprinkle on top of the wort. (Links to
Fermentis and
Lallemand product information).
for 1 gal batches in the OG 40-60 range, I get good results by sprinking the yeast on top of the wort (it settles fast). In the past, I've used 2.5 g (roughly 1/4 of the package). Recently, I started using 1.25 - 1.5 and so far the results have been good. For me partially opened packages store well for a couple of months (others mention longer timeframes). I close the package tightly with a rubber band (others will vacuum seal it) and toss it back in the fridge.
edit: formatting