Just in case you forgot that the goa'uld were evil, this episode shows just how evil. It also introduces Cassandra, the little girl who'll reappear a few times in future episodes. As a result of Cassandra being the only survivor of a plague on her home planet, Sam gets to showcase her maternal instincts (and even Teal'c and Jack get to show their soft sides!). I'm not sure if it was deliberate or not, but this does seem to take away some of the 'strong female character' vibe she had going in the previous episode, Hathor.
The goa'uld Nirrti is mentioned in this episode, as an enemy of Apophis, but still trying to destroy Earth (or at least our Stargate) for some reason. Hintings of a larger goa'uld conspiracy (i.e. the System Lords) perhaps? Nirrti is also referred to as a man, though in future episodes she will appear in a female host (and showing a female personality). It's entirely possible that the symbiote switched since Teal'c heard about it, or that he was just misinformed or made the wrong assumption.
Something I've noticed over the past few episodes is that general Hammond has stopped wearing his dress coat. Still long sleeves on his shirt, though. Without the coat, you can tell he's chubby, but it makes him look more casual and somehow more relatable. Perhaps it's because you see more of the person behind the rank, insignia and ribbons. I've also noticed that we're seeing a LOT of dr. Frasier in these early episodes - she's become as important and regularly appearing as general Hammond, despite having been introduced once the show had already commenced. Of course, I'm not complaining - Janet is one of my favourite supporting characters, and I wish they'd put her in even more.