As Terretta mentions, you'll be offering "membership interests" and as far as I remember from our experience with an LLC, you don't offer shares but "units".

You'll have to detail unit interests in your operating agreements and set up unit subscription agreements with your employees. Most of it is akin to what you'd do with a C-corp but the terminology is a bit different.

One note: If you're contemplating raising outside investment in the future from angels or VCs, a C-corp may be preferable as it appears to be their preferred structure (not a hard and fast rule but a preference). I've heard LLC to C corp "conversions" can be less than pleasant.