Coming up to the first monument of the year, it's hard not to want to race ahead and start picking winners. But for now, let's just take a look at the course.
Milan-San Remo is truly unique in one critical respect: it's nearly 300 freaking kilometers long! And it's always been this way, usually at least 280km. This makes it the longest of the Classics: Flanders and Roubaix both check in at just under 260km; Liege at 262, Amstel at 253, and the midweek tilts La Fleche and Gent-Wevelgem just over 200km. This year's MSR will check in at 294km.
The route rarely changes much. The main features are the Passo del Turchino at roughly the halfway point, where conditions can get pretty nasty save for the tunnel at the summit; and the climbs of the Cipressa and Poggio with roughly 20 and 5km remaining, respectively. The latter two were added since 1960 to what used to be almost entirely flat but for the Turchino. Smaller hills include the Capes: Capo Mele, Capo Berta and Capo Cerva. All three are in this year, making it a "hilly" version (though I can't seem to find recent editions that excluded them).
Most races can be won by either a sprinter or a climber, and of course a long attack. But la Corsa Primavera with its great length and late undulation can favor any of several rider types. The rouleurs who can tap out seven hours of tempo will be fresher than the smaller riders, assuming the pace is high. Often times the race ends in a mass sprint on the Via Roma, though only the sprinters who can do long tempo and get over the Cipressa and Poggio intact, with something left in their legs, can win. Classics riders who can climb can try their luck with attacking on the Poggio, which works often enough... as long as you can sustain a small gap for the 5km plummet and flat run-in, with the main field breathing down your neck.
Basically, it's a long and sometimes dull race for a while, but the last hour or so is completely unpredictable... and well worth the wait.
More resources and handicapping tomorrow, but for now here's an English almost-official site where you could get lost for a while: