Newbie -all readings high

Greetings!

I have a 37 gal Oceanic that is 11 days old. Long story short, day one I
put in chlorine treated and stress coated water, 2 live plants, a tiny
snail, 2 small decorations and some decorative 'river' glass, and 3 smallish
tiger barbs that I had gotten at Wal-Mart and nearly suffocated when I put
them in a small Beta tank over night (the things we do for our kids :-)).
About 5 days later I did a 20% water change. Also, at some point about 9
days ago one of the tigers died. Five or six days ago I added a packet of
Bio-Spiro (sp?) from a LFS, but they weren't very friendly or informative.
Then 2 days later added 2 green barbs, 2 albino tiger barbs, 2 good sized
snails, another plant, and 2 more small decoration (from PetsMart). I
probably did not do a good job of choosing fish, but now we are attached,
especially to the 2 little Wal-Mart tigers. Yesterday I went to another
LFS, friendly and helpful, and I got a MagnaFloat and a test kit.

My water had been a bit cloudy but it cleared up yesterday. I was probably
feeding them too much. This evening I test the water and I was surprised to
find that it isn't in great shape. Maybe 11 days isn't enough time and if I
am doing the right things it will all work out. The fish look happy, even
if they are a bit mean to each other.

The PH is 7.75.
The Ammonia is around 1 ppm.
The nitrite is between 2 and 5 ppm.

What do you recommend? Also, any advice on when I can add fish and what
kinds would be appreciated.

Thanks,

Dave Peck