Ok, so I'm looking to build a pretty simple fireplace mantel and just wanted some opinions to come up with a plan before I start. I'm thinking of building a mantel as described in this video:
http://www.diylife.com/2008/08/13/ho...eplace-mantle/
Basically it uses 1x lumber, with the edges mitered to 45 degree angles, with the mitered edges glued and nailed together, and finally attached to the wall via a ledger that it slips over. It's a very simple/square designed mantel, no fancy molding or anything. I have an 18gauge brad nailer, and I can borrow a friends table saw, so tools wise I'm a-ok.
One big question I had is what wood would be best? Oak or pine? The video recommends clear pine, but I thought pine sometimes took stains unevenly, but perhaps with a very dark stain it doesn't really matter? Also, would the mantel shelf be sufficiently strong with simply 45 degree mitered corners, glue and small brad nails? I know the attachment to the wall should be rock solid with a ledger, but I just want to make sure the shelf itself is strong enough. I'd estimate its final dimensions to be somewhere around 48"W x 5" high x ~6"deep.
I'm very unfamiliar/new to carpentry (I've built a couple things out of wood, but nothing I could proudly post pictures of

), so any suggestions are very much appreciated.