Welcome jd. You will certainly not regret your choice to invest in silver or any pm for that matter.
Premiums are truely based on what you buy. If you are buying silver for investment purposes I would probably stay away from the 90% silver coinage and the numismatics and stay with 999+ fine silver, although it's not a bad idea to atleast have a couple small bags of the 90% stuff around for other reasons.
Bigger bars usually carry a lower premium almost anywhere you shop. I prefer local coin shops over online dealers but to each there own. In the local coin shops where I live, the owners of the stores are willing to negotiate on premiums, give discounts for larger purchases and often times round down on the premium price to make the price an even number for easier calculation (yes it's true).
There are a couple good tools that if you check in the marketplace section of this forum that you can compare some current premiums from a few top online dealers side by side. As far as shopping around locally I can try to help you, I will give you the prices of the three local shops in my area so you can get an idea of what a local shop will probably run you.
Shop 1 - $4 over spot for ASE (only $2.50 per oz over if you buy a tube), $3 over for Maple Leafs and Other Gov't Bullion, $2 over on Englehard and JM products and $1 over for everything else, Bars over 10 oz $.75 over spot per oz.
Shop 2 - $1 over on any 10oz bars, $1.50 over for 1 oz generic bars and rounds, $2.50 over for brand name refiners and $3.50 for any Gov't issued bullion including ASE and Maples. $.50 off per oz on any purchases of one 1 once bars/rounds 10oz or more.
Shop 3 - $1 over for generic 1oz bars/rounds, $2 over for premium bars/rounds, $3 over for ASE and Maples. $.25 cents off per oz on any combination of more then 10 oz. 10 oz bars are $1 over... but if you buy a one oz to make it more then 10 oz the $.25 off discount applies.
Hope this gives you some help. Also don't forget to factor shipping if purchasing online. Be sure to shop around also continue to browse the forums for other tips on purchasing PM's.... there have been a couple first time buyers on the site before they made their purchases so we all offered some good advice on taking the plunge into metals.