The first couple of things I thought of when I read your post were these:
1) The extra "tsu" you read wasn't really a "tsu" at all, but a "small tsu" (compare つ and っ). This represents a "doubled consonant" in Japanese, which takes an extra mora (syllable) 's worth of time. There is also a small ya, yu, and yo (ゃゅょ), which are used to create syllables like "kya" and "ryo".
Focus on learning *all* of Hiragana before you start trying to read anything. Go as fast as you can, I'd say, since it's just brute memorization (googling "hiragana flash cards" might be a good idea), but don't get ahead of yourself. Also, be on the lookout for look-alike characters - you mixed up ば 'ba' with ぼ 'bo'.
2) Trying to read children's books is a great idea, once you know at least a little Japanese grammar and you can identify particles like は、が、を、に、で and so on. I do agree that starting Kanji ASAP is a good idea as well. At your stage though, "fake Japanese" example sentences might be more helpful than authentic text.
If you want to go the immersion route, though, grab the Firefox addon "
rikaichan", a pop-up dictionary (make sure to download the dictionary file too), and try exploring the web as well.