My time away from hockey started late April '07. Torn ACL, MCL, and both menisci. Went through the whole rehab, then ~3 weeks after completeling rehab and beginning to skate again, I was in a car crash and fractured the shin in the same leg. Along with another slight meniscus tear. Just had my first game 2 Fridays ago...so 29 months.
Abotu two months between sumer play and them opening up the ice here at school.
As for sharpening skates, no you do not. The blades are metal. Unless they've been damp and have rusted, they do not spontaneously get dull. You might want to resharpen them if you've skated on that sharpening a bit already, but if it was sharp when you last used them they should be sharp now.
Since I joined a league: 2 weeks. I only played on Wednesday mornings at that point and the two weeks were Christmas Eve and New Year's Eve. I don't get why both games were canceled and it seemed like the longest two weeks since I started playing hockey.
More recently, a couple years ago I tore my groin and was out for six weeks. But that wasn't long enough, because in my second game back I re-tore it, and was out for another seven weeks. 1.25 games in 14 weeks drove my crazy.
The last 2 years i have not played summer hockey (getting too old). This year is actually my longest without even being on the ice, we finished in april and i dont start till Nov 1. Might go skating 2 or 3 times before. Im trying to get as much diving in before the water gets too cold, so i might not have time to skate before my first game.