A lot of it depends on the weather, KatyLou. I believe you are about to get another bout of wet, cold weather after some reasonably warm days. That isn't to say that you couldn't aerate your lawn at any time during the year if it needs it. If it really IS like a swimming pool, and isn't draining properly, perhaps it needs something more than spiking, and you should be thinking of more drastic restructuring before you start using mosskillers and lawnfood. Addressing the drainage is really the first and most important thing to be done. Once you have that sorted, then, again depending on the weather, you could start using a combined mosskiller/lawn sand. The moss should blacken THEN you can scarify it all out. That wouldn't be appropriate much before the middle-end of this month, and then feeding the lawn I would put off until around mid-April, when the weather should have reliably improved. A little late in the day, perhaps, but Welcome to GoY!

Hello! Gattina is totally right ... you need to address the general drainage, or you will have a perpetual battle against the moss returning every year with the same or similar level of annual correction. You have a choice of either a moss lawn or a boggy plant area for plants such as yellow flags and marsh marigolds, etc, or a major restructuring and drainage initiative to get a decent grass lawn.