So after talking a bit about what she really enjoys about playing with my trains, TwinGirl and I settled on starting out with a simple Inglenook puzzle on a shelf as her first train layout. She really enjoys building and breaking up trains, and has limited space in her room. So, not really having dabbled in HO since I was a kid, I have a few questions... My calculations - based on Atlas Code 100 track, 50 scale foot cars and an 80 scale foot loco - show that I'll need about 6-1/2 linear feet to lay the track. I'll probably put it on an 8-foot shelf with an inch of foam on top. I'll probably wire this DC, since she'll only be operating one locomotive and we don't have the budget for a second DCC setup. Right now I'm thinking manual ground throws... but I may revisit that given the whole "reaching over/around cars on a shelf" thing... A few questions, in no particular order. I'm fairly familiar with the basic construction techniques, but not with some scale-specific issues... 1) How much minimum space should I leave in the foreground? In N I would shoot for at least 2 inches, so I'm guessing... 4? 2) Track spacing in the yard tracks? NMRA S-8 says 2-1/16" in yards... I'm thinking 2-1/4 or 2-1/2 to give her a little extra room? 3) Track selection. Bulletproof operation is essential, since this will be a shelf on a wall operated by a 10-year-old. But she'd like it to look nice as well. In N, Kato has the rep for being bulletproof... is that still so on HO? Assuming reasonable care in installation, is the Code 83 stuff robust enough? She's not rough on her things at all. 3b) Are the Kato turnouts compatible with Caboose (or similar) ground throws? That's all for now... I'm sure I'll have more questions later. I appreciate the advice, all!