The first two Spiritual Stones come from the first two dungeons, so naturally, they are meant to ease you into the game. I just started a 3-heart run of OoT, which is only my second ever playthrough of the game, so I know that for a fact.
![tongue :P :P](/forum/styles/default/xenforo/smilies/theme_icon3.gif)
Btw, there are some spoilers, so spoiler tags should be found in this thread.
Anyway, Inside the Deku Tree and Dondongo's Cavern are pretty easy. Quite easy. Okay, very easy. The difficulty kind of spikes in Jabu-Jabu's Belly, if you didn't know what you were doing, like I did. It had a different feel in the game, a different atmosphere. It was gross. Just disgusting. It could have weirded anyone out, or just made you uncomfortable enough to make you rush through rooms in the dungeon. Once you figure it out and steel your stomach, it gets simple.
Yes, I believe getting the three Stones is considerably easy, even for beginners. It's a good challenge, but nothing too rigorous.