Block or seam first? How to's! Help!

I have finished knitting my first baby sweater, it’s a raglan sweater. Now I need some advice on what to do next. Do I seam? Do I block? How do I block for cotton bamboo? It’s looking good and I don’t want to spoil it. What is the best seaming techniques. Maybe someone has some links for videos on seaming? I have seamed before but it has been a while. I just don’t know what the best way to start is. Thanks a bunch. I would not have gotten this far with this sweater if it wasn’t for the forum.

Thanks!

There’s a video for the mattress stitch under Finishing on the Tips page. That should do it.