Re: Pine SLABS
The simple thing to do is paint the ends (as logs) thoroughly with EXTERIOR latex paint (interior may not bold well enough to the end grain, and won't last in the outdoors). That'll hold 'em until/after you slab 'em up.
After slabbing, be prepared to wait at least one year per inch of thickness for 'em to dry. Sticker well, especially big slabs. Protect from sunlight, but allow air to circulate freely around & through the stack.
Good luck encouraging the bark to stay on. It USUALLY falls off as the wood dries & shrinks, but the bark doesn't shrink with it. Not always - sometimes the bark stays just fine. USUALLY it comes off, though.
-- Tim --
My sigline had gotten... REALLY OLD, so it's nearly time to think up something new to put here.