A long time ago I also crashed and went to ER.

+1 on asmallsol's advice on tegaderm. Use 2nd skin as well. There's a new competitor in a shiny pack. DON'T get it, it sucks, waste of money. I don't remember what it was except it had a familiar brand name on it.

Note: Tegaderm looks like Saran Wrap. 2nd Skin looks like 2 layers of Saran Wrap with a layer of clear gelatin 2mm thick between the two layers of the Saran Wrap. I think 2nd Skin is more soothing for fresh wounds because it feels cool, I think Tegaderm is better for smooth or healing wounds because it's smoother.

Also there is a tegaderm with a mountain bike shoe on the packaging (I think it's water proof). I think the regular stuff works better.

+1 on putting gauze on top of the clear stuff (tegaderm/2nd skin) to keep the clear stuff in place. Put huge swaths of gauze on and then lots of tape to keep it in place. For large swaths the fishnet stuff (check out Valverde's leg in this year's Tour) or ACE type bandage/wraps work well too. You have to cover the clear stuff, otherwise your very expensive tegaderm/2nd skin gets peeled off when you put your shirt or pants on.

Shave anywhere the tape will go. It'll be hairless anyway, but if you shave it first, it hurts less

+1 on keeping the clear stuff on for a while, i.e. days - take it off only when it gets gross underneath (you'll know it when you see it - yellow, green, brown, anything except pink/red/white). When your wound is close to healed you might leave it on for a week or two - that's my experience. 2nd skin, because it has so much water in it, gets a bit mushy after a week. Tegaderm is better for the long haul (2 weeks, at which point you're probably good to go).

Use a numbing antiseptic liquid to clean the wounds. I got this translucent blue bottle with a squirt top. First spray down the wound. Wait about 30-60-90-120 seconds to let the numbing part get going, otherwise there is no numbing. Spray a lot to get more of that numbing stuff on. Then, after a few test touches with a gauze pad (the wound will feel swollen but it won't hurt), go to it and scrub out the wound. Rinse generously with the numbing antiseptic stuff, you want things clean. Then put your new tegaderm/2nd skin on. This cleaning step is critical since it keeps everything nice and clean and fresh.

Check your head/scalp for bruising. You will be surprised. It'll also give you an idea of where you hit your head because you obviously did. Then you can re-examine your helmet and be even more amazed at how much shock it absorbed. Days after my biggest ever helmet impact, someone pointed out the side of my head was purple, a huge area, basically ear to top, all the way from front to back, but all in my hair line. I checked and it was. I then looked at my helmet and saw that not only did it crack in a couple spots (which were obvious), the whole side was compressed about 1/2". Insane. I didn't realize the shell wasn't supposed to be loose and squishy. And right after I hit the ground I claimed to be totally fine. Luckily the EMT there disagreed with me.

Once your head is okay the rest follows quickly.

It won't be cheap buying all this stuff, but it really, really helps. Figure 2-3-4 boxes of the clear stuff per round, twice that much gauze, and appropriate tape/ACE/whatever to hold the gauze. I'd use almost a full bottle of that spray stuff per round too. Figure 3-5 rounds of clean/redress before the wounds are nice and pink and have virgin skin on them. My first aid box has maybe 15 ACE bandage rolls (washed and re-rolled), about 4-6 left over "sticks to itself" wrinkly white faux-ACE bandage disposable stuff, about 10-20 boxes of mostly used gauze pads of varying sizes, and maybe 10 mostly used rolls of first aid tape (I like 1/2" to 1" tape, the skinny stuff is useless). I use up all the antiseptic wash I buy, and I have a couple half used antiseptic goo stuff.

Oh, finally, don't skip the little spots. You'll pay a lot of attention to the big scrapes everywhere and ignore the tiny dime-sized road rash. In a week that dime sized road rash will be stinging and swollen and hurt like a mofo while all the big stuff is almost healed. Take care of EVERY SINGLE wound. Bandages with lots of antiseptic goo for the little ones (cover with first aid tape if it's in a "high traffic" area), 1/2 pieces of tegaderm covered in first aid tape for the coin-sized bits. The little tegaderms you'll leave for a while, just make sure they're ALL cleaned out before you dress them up.

Learned the hard way,
cdr