Just starting out...are my kids too young?

[New Haven I-5]

 Why not use Lionel's Thomas & Friends line.

[arkansasrailfan]

I have had trains since I was 2 or 3, but a hardcore railfan from day 1--YEE HAW!!!!!!!
I have also gotten my 3 year old counsin into trains, but he like real, Thomas, and Polor Express, and has PE and Thomas trains(just toys)

[FunWithTrains]

That sounds  like a good idea.  I have kids aged 3 and 5.  They love trains, but have been pretty hard on some of my HO models.  I believe O or G (LGB is really sturdy) are probably best.

Regards,

Rob