If you have any bird nest-boxes in your garden, you should now think about clearing out any debris left from the last nesting season. Ideally you should clear out old nests at the end of the breeding season in autumn - this helps prevent disease and parasites from affecting birds which use your boxes. If you did this and put in clean insulating material, such straw, for roosting birds over the winter, you should now clear that out too.
It's not too late to put up new nest-boxes either. In general, try to position them facing away from the prevailing wind and rain and out of direct sunlight. You can find more information on nest-boxes on the RSPB