Seriouslifter, check out
www.fitday.com to track your calories.
Bottom line, if you aren't gaining weight, you aren't eating enough calories.
So, track your calories for 1-2 weeks, find your daily average, then increase by 10-15% until you gain about 1 pound per week.
Here are some general guidelines that I follow, although they aren't exactly conventional:
1. Eat a minimum of 1 gram of protein per pound of body weight.
2. Eat a minimum of 0.5 gram of fat per pound of body weight.
3. Every meal has meat (beef, chicken, pork, or fish) or protein powder (very rare).
4. Every meal has veggies (spinach, carrots, broccoli) or fruit (apple, orange, banana, etc.).
5. Every meal has nuts (cashews, walnuts, almonds, peanuts).
6. Main meals (breakfast, lunch, dinner) have a complex carb (brown rice, pasta, potato, etc.) depending on goals.