Training legs once a week won't get you big or strong. Simple as that. After my years of training, I've worked up to pretty crazy frequency. I don't put any time limits on my training. I've done heavy overhead pressing, then heavy benching the next day. I've done a speed squat day followed by a max effort deadlift day.
My point is, don't limit yourself with too many rules, and don't worry about overtraining. I think everyone who wants to get big and strong should squat at least twice a week, and deadlift at least once. I'm currently just switching back and forth, upper body, lower body, upper body, lower body, training pretty much every day. The reason this works is that I shift my focus. One upper body day will be heavy benching with a little upper back work, then the next upper body day will be heavy overhead pressing with tons of explosive pullups. Every upper body muscle is hit on an upper body day, but some get hit more and harder than others on any given day.
I'm not suggesting that a rank beginner trains like I train, but my point remains the same. If you want to get better at playing pool, playing once a week until you pass out isn't going to make you better. But playing every day will.
I don't care about soreness. It's been a long time since I have. You'll find that spreading your training out through several sessions per week keeps your soreness from being nearly as acute and intense as it is when you bash the crap out of a muscle once a week.
I'm with the others, go with a fullbody routine. If you really want to get some results, spend one of your rest days pushing or pulling something heavy. There are lots of tutorials online about making a homemade pulling sled. I welded mine together, but all you need is an old tire, and eye bolt, and some rope. If you train on monday, wednesday and friday, then go out saturday morning and pull something heavy until you can barely stand.
Everyone is so afraid to push themselves! They'll destroy their muscle when it's "leg day", then make sure they get tons of "rest". BS. While they're resting I'm getting strong.
Current PRs at 242, raw w/ wraps- 525, 355, 605, 1485
Roboro tui, perimo vester adversarius
(Build yourself, destroy your enemy)