Honestly, there are a lot of great people here, but I'd start by having a look at members like Tn21.
Obviously it depends on what you are looking for & your budget, but if you are a beginner just looking for one coin to start, I have just made my second purchase from him.
He's polite, dispatches fast & I was very happy with the first Britannia I got from him (which is why I came back for another.)
There are other traders who are selling whole tubes at a time, but my budget doesn't stretch that far.
I'm not a premium member yet, I want to get Christmas out of the way before being that tempted.
It is a bit of a pain wading through the pages of sales threads to find the ones that are still open & visible to non members, but there can be nice things to find (I got a couple of lovely Valiants from someone else recently)
If you look at members who sell or buy things, they have a rating under their names.
The more positive ratings, the more people you already know have traded with that member & been happy.
You don't need to rush to buy though, take some time & ask yourself what it is you are trying to buy silver for?
Are you collecting beautiful things? coins that you feel have historical significance? for the long or short term? bullion to resell?
Will GCT become an issue in the future in whatever your plan for your precious metals is?
You need to work out a budget (I've seen enough things I'd have loved to buy to get a nice house in a posh part of the country in just the past few months, & something else shiny turns up pretty much every day), start watching the prices & reading up about stuff.
You need to find out how to spot fakes & learn how to do that yourself so you can feel more confident in what you buy.
You need to think about how you are going to keep records of what you buy & where you are going to store it.
The precious metals will still be there when you are ready to buy some.
Who knows, prices may plunge next week & stuff could be even cheaper than this week (or of course, the opposite could happen).
Precious metals are a slow game, so there is no massive hurry.
My dream coin is a Lydford penny, which would have special significance for me.
For the rest, I collect writers & scientists, plus general bullion which I hope will insulate my money from the deflation it seems to experience as cash.
Everyone else here has their own completely different targets they are working towards, with massively different budgets.
Figure out who you are & go from there.
Be warned though, precious metals are almost addictive.
There is something about having a really gorgeous coin of your own that brings out the Gollum in you!