I don't think they have a newsletter.. at least the last time I asked, they just have facebook and their blog that they never update
They do have an email newsletter, though they only use it for big sales. Just sign up via their website. It's typically the same as what they post on FB, so no need to do both though.
Marine Depot and Salty Supply are also running pre-Black Friday promotions (Door Buster and Black Friday Countdown). Sign up for their email newsletter on their site. Salty Supply had a really good deal on a Tunze Osmolator (35% off) a couple of days ago. I'm also waiting for BRS' Black Friday sale which is typically very good every year, though I noticed their prices aren't the cheapest anymore.
Regarding the LFS, I buy certain items such as livestock and specialty items from them -- I'll discuss this in a bit -- but I buy the bulk of my items online. The money saved is typically spent at the LFS anyway. This gives me some "cred" with my CFO (aka the wife) which goes a long way.
I typically walk in with cash to the LFS and they were willing to work with me to get those specialty items at a good price, many times better than what an online retailer charges. I bought all of my wavemakers and lighting (made by the same company and they all work wirelessly together, if you catch my drift) though a LFS and was very happy with the price. I doesn't hurt to ask a LFS to work with you, especially if you're a good customer, you just can't be an a-hole about it. I think many LFS get that people shop online, and if their prices aren't comparable, then people will simply buy online. However, as customers, we need to realize that the LFS will stock many items -- such as food and small supplies -- as a convenience for the customer and we should be willing to pay accordingly.