I live and snowboard in the lake tahoe area, and in my opinion some of the most enjoyable riding is in the spring. If its warm enough to keep the snow soft, then it is like poor mans powder and very forgiving. However, if it has been below freezing at night, dont go too early in the morning, wait for the sun to soften the snow a bit, and stay on the southern facing slopes. Be aware that shady areas will still be frozen. Conditions will vary, be prepared for anything.
Now for some tips on learning to ride. Dont focus on your skimboard experience. I can assure that it is not similar other than sliding on a board. For one thing, you can get out of control on a snowboard and crash at 60+ mph. I have personally been speed checked at over 80 mph. When you crash ( you will crash) keep your arms tucked in, or you risk shoulder dislocation. My riding partner has had multiple shoulder surgeries thanks to this.
You will be tempted to ride on very flat bunny hills, but it is difficult to go slow on a board and not catch edges. Riding on a medium steepness slope will actually be easier for you, since it is easier to always have one edge or the other engaged. If you are having trouble on a flat slope, try something a little steeper.
When you are riding, you should have an athletic, crouched stance. Bend at the knees, not the waist. Bend at the knees, not the waist. Bend at the knees, not the waist. When you bend at the waist, your center of gravity is too far out over your toe edge. You will fall on your face, and exhaust your back muscles. Every noob rider struggles with this.
As you travel down the mountain, especially as you gain speed, you will instinctively lean back from the downhill. This takes weight off of the nose of your board, and you will not be able to turn. Keep an aggressive stance and lean into the nose of your board. Imagine trying to turn a car when your front wheels are not on the ground.
Ok, this is important. As you are learning, you will not be making quick turns and you will be using the whole run to make your turns. Be aware of other skiers and riders who are uphill of you as you turn back and forth across the run. Some of them will be going by very quickly in a straight line and not turning at all. Bunny hills are usually at the bottom of the mountain, and expert skiers and riders will be present. Be aware of blind areas and whether you are in one. If you crash in a blind spot, get out of it as quickly as possible. When you stop to rest, make sure that you are visible to uphill riders from a long ways away.
You will see riders in the trees, slashing fresh pow and having fun. DO NOT GO IN THE TREES YOURSELF. They will kill you.
I ride all of the mountains around here, and I would recommend Heavenly for you. Heavenly is where I take my wife. There are lots of medium steepness, wide open runs, with plenty of room to turn and learn. The staff is friendly, and pretty girls are everywhere. Big Dipper is a nice run with an awesome view. You can see my house in the valley from the Dipper lift. Oh, being somewhat duck foot is not a disadvantage at all. To the contrary actually.
If you have more questions, just shoot me a pm. I love riding and enjoy helping people learn the sport.
