You already have some great advice here - so let me just weighin with a little beginers perspective, what I found difficult, etc.
First off, check that patterson reel before you go into the dark - mine was snapped together wrong ( the parts accepting the film were about 45 degrees of each other...). I bought the tank and reel, and didn't even look at the reel. So... I had to figure out what was wrong in total darkness, while holding a roll of "naked" film in one hand...
Sounds like I belong in the special olympics... but its just a little example of what happens when you get to eager and too excited and just want to get on with it! And I really had high hopes for the negative, so I didn't have the option to turn on the light and just say "screw it"....
The other thing is - when you get the end and pull off that tape DO IT SLOWLY! I thought it was just an overcautious physics nut that warned of the electrical discharge that may take place if you pull the tape off too fast... but its not. I saw it with me own two eyes, it happens, GO SLOW.
Wash your hands and dry them thoroughly - I wipe them down with rubbing alcohol and wait a couple minutes, because you have to cradle that MF film in your hand while unrolling the backing tape, etc. its touching your skin longer than a roll of 35mm - you want no oils or anyting else getting in there.
Also, the Paterson reels have those tiny grooves that the film sits in. I am sure I don't have to tellyou all about the clenliness of it being important, but those suckers NEVER DRY! They have to be facing open side down, or better yet, give them a wipe with a clean pieceof paper towel or somethig else that won't lint. I had some nasty little marks on the edges of my negs untilI realized there was water in those grooves.
What else... well, the film is thinner, so its not as sturdy, or rather rigid - so be careful not to crease it - I find grabbing the end and pulling it into the real for a few inches helps, rather than relying entirely on the ratchet action.
If I was to do it over, I would doit in the light a few times with a practice roll - better advice I have never heard. Of course, I didn't, and while the pics came out, when I did it was 45 minutes later, sweating like a pig, frustrated and with a roll of filme that was a bit worn around the edges
Best of luck - if you have only shot 35mm so far, that first MF neg will blow your mind! As I am sure that first LF one will do for mine...what's that honey? NO, I am NOT buying another camera, don'tbe silly....shhhhhhh, she's listening
