I'm the opposite- I'm terrified of canulas- for anything, even sedation!! I get nervous having a PICC line put in too but once it's in I'm so much happier. I don't know if it's the same thing as a long line but I suspect it is. I had long lines a few times as a child and it seems the same thing.
Basically you get taken to x-ray (I think it can be done bedside too but where I go they go to xray), they do an ultra sound of your upper arm (bicep area kinda), find a good vein and then do a couple of bee-sting shots to numb the area. That's the worst bit for me. After that, it's a lot of pushing and tugging and once or twice you feel a strange sensation if they can't advance the line. After it's in it can kinda be a bit throbb-y for about a day but paracetemol takes care of this. You need to have the dressing changed after about three days I think too. But I mean you can go about your normal day without fear of it tissuing or anything and it's usually very hidden.
The only problem I had with mine is that having had IVs three times in the space of about 18months, my veins in my right arm closed/blocked with scar tissue so they had to try the left arm and it was a bit of hassle eventually finding a vein in my left. Thankfully it's been three months since my last IVs so the longer I last without -should I ever need them again-, the more healing time there is.