One book that I would have loved to purchase when I began lifting is Starting Strength, no affiliation. In this book the authors recommend starting with the bar (a standard olympic bar is ~45 lbs). This sounds counterintuitive, especially for a heavier person, but there are reasons for this. When learning the exercise, form corrections are best made before weight is added to the bar. After the exercise is learned, one should always start the exercise warm up sets with the bar to get the blood flowing, warm up tendons/ligaments, and other things. I'm summarizing b/c I don't fully remember, but I read enough to know it's important, and I have done it enough to know that it helps when your legs are still sore from two days ago, but every day is squat day, that easing into your warm up sets with the bar isn't so bad. :-)
I'll add that in that book there are logical progressions for adding weight to the exercises, if that's your next question. If you feel like you're not progressing "fast enough", take your ego out of the picture and just follow the routine, they've done all the heavy lifting for you. Odds are if you stick to it you'll naturally elevate to where you should be.
Note that this isn't just for gaining weight. Heavier people will lose weight while gaining muscle (such as myself), while those with less mass will gain weight. The diet is then difference. So in the OP's case, this is a viable option although it goes against the mantra of 'low weight more reps'. Partly because while that advice works, once your body adapts to that low weight at a certain # of reps, you will no longer tone and have to increase the weight to get the same effect. Not to mention the effects on the body's metabolism are different.