I have  two questions about training  for my first 100 and I think this might be the best place to ask them.

How long should my longest long run be before the race?

if I do a 50 miler as part of training, how for should I space the races? Like a 2 months, a month or less

I have lots more questions but that it for now.

Thanks

If you can work in a 100K, great; but I finished my 100 with just a 50-miler 8 weeks out.  (I also worked in a few back-to-back long runs).  For my upcoming 100 (Rocky Raccoon this weekend) I ran a 50-miler 5 weeks out, as well as ran several B2Bs.  As for when to run your longest run, it depends on your endurance base and how quickly you recover.  If you're relatively new to long distances, then I'd give it more time (6-8 weeks).

Thanks for the advice everyone. I'll plan on doing a 50 miler or 100k in mid march.

For your first 100, I would even say a 50K heading in could be good enough. Longer, there is higher injury risk.

But if you have never run > 50K, then probably best to get something longer in.

Ah.  I paced 60ish miles of Keys two years ago.  That race is significantly different than the 100s most folks probably had in their brains when reading your question.  It is road, board flat, and hot/humid.

Enjoy Seven Mile Bridge.  It is a massively trippy experience after you've been running all day.  The year I paced, some of the aid stations for the solo race were unattended ice chests and water jugs.  Most of which got pilfered through the day.  Just before we went across the bridge pre-dusk, my job became "beg relay crews for water".  That was some day.

Worry less about finding mountain/trail 50 milers or 50 ks although obviously the 'time on your feet' aspect would help.  You need to be ready for the kind of flat road pounding 100 miles is going to require.  I'd be running some marathons and road 50ks (and/or a road 50 miler) when you can and doubling up on weekends.  Also, there's the Palm 100 in March... road 100k put on by the same dude.  That would be helpful, but as bhearn notes, perhaps increases the chance of injury.  Dunno.  That's the progression I'd use, though.

You don't have to have a race - I think 40 miles is plenty of distance - Run at a pace you think you could ideal hold for 100 miles ... including walk breaks and eating like you would do for 100 miles ... on a similar course as the 100 miler.  I personally like to think in terms of time.  A run of 6-8 hours is plenty long.  I would do a couple easy runs of 4 hours and 1 or 2 in the 6+ hour range.

I'm doing the Florida keys 100.  I ran the lookout mountain 50 mile in December and two 50Ks. My  trouble right now is finding a 50 mile in my time frame that's close to me (Maryland).  But worst comes to worse I'll do a back to back  50k and and a 20 miler.

Thanks for the race suggestions. I think I'm going to do the Bull Run Run 50 Miler on April 13th.  I was definitely considering taking Buzzie and Dopplebock's advise and just  not doing a race. BUT its hard to resist a race that's relatively close to my house and in my time frame.

Since Keys is so flat, you could do a timed race a few weeks out, 12 or 24-hour loop course, for time on your feet.