I am new to this too and have never winterized a trailer. I asked tons of questions about it when I purchased my TT and it seems pretty easy. However, I was thinking that for the first time I might pay them to do it. $60 is a little to pay to know it is done right. But, I planed on telling them they had to teach me what to do while they were doing it and taking notes. The following year I would do it myself.
Otherwise I think it is very easy and straight foward. I think anyone could do it themselves but there is nothing like a little confidence booster. $10's plus for the anti-freeze, what's another $50 when you're not sure? Just my $0.02. Good luck.
I am moving to FL from NJ in 4 weeks so winterizing hopefully won't even be a concern.
'05 Solaris 264 SR
'05 Nissan Titan