You can pretty much hike in England in all four seasons, but to hike the Lakes in winter requires serious mountain experience, not so much because of technical difficulties, but to cope with the harsh weather. More temperate minded hikers (i.e., the rest of us) prefer spring, summer, and fall. Warning: Summer temperatures can be surprisingly hot, and almost none of the route is shaded, so bring a sun hat.
Get a plastic map case that you can wear around your neck to keep maps close to hand. If you don't find one at your local outfitter, they are readily available in England. Also, gaiters are a must, or your boots will be filled with mud. You'll want decent rain gear and a layer of warm clothes.
Most guidebooks and maps break the trail into twelve suggested stages, each of which is presumably one day's hike. The Brits live up to their stiff-upper-lip reputation and gamely plod along, but as an experienced long-distance hiker, my opinion is that some of these segments are too long for comfortable hiking. Doing the Coast-to-Coast in twelve days (that's sixteen miles a day) is not everyone's cup of tea. Far more comfortable is a thirteen-, fourteen-, or even fifteen-day schedule and, if you like, you can take more time than that. There are lots of ways to customize the stages to your own hiking style, so by all means, figure out a plan that's right for you. A few specific recommendations:
First, break yourself in gently by splitting up the first stage. Conveniently, the first six miles of the hike basically go in a circle: You start by rambling in a northeasterly direction along spectacular St. Bees Head before you finally turn west. If you arrive in St. Bees by mid afternoon, you can easily walk those miles and return (via a two-mile footpath) to St. Bees for a bed and a meal. The next day will be shorter; you'll thank yourself for your foresight.
Second, there is a seventeen-mile stretch in the Lakes District from Rothswaite to Patterdale that should be broken up. This is in serious mountain country, with two major ascents. It's not only a hard grunt for one day, but doing it in one day will force you to forego some absolutely glorious high-country alternate routes that are longer, harder, and worth every step (in good weather, that is). What's the downside of taking your time? Poor you: You'll have to spend the balance of a short hiking day in beautiful Glasmere, where you can visit the home of William Wordsworth.
Finally, the twenty-three-mile walk from Richmond to Ingleby Cross is fast, flat, and easy, but too long for most people's comfort. There's a perfectly good pub to stay at in Danby Wiske, at about the fourteen-mile point.
Details mentioned in this article were accurate at the time of publication