Here are some resources that we recommend. Want even more? See this list!

- Studying Challenging and Cool Math Year-Round
- Learning Unlimited Programs: day- and weekend-long festivals of learning, much in the style of Mathcamp classes.
- Math Circles: weekly or monthly gatherings exploring cool topics in math. Find a circle near you or start your own!

- Problems, Problem Solving, and Math Competitions
- The Art of Problem Solving (AoPS): a problem solving website with classes and active message boards. Lots of Mathcamp students (and even staff!) post and read regularly on the AoPS message boards.
- USA Mathematical Talent Search (USAMTS): a nationwide mail-in math competition open to all US high school students.
- The Centre for Education in Mathematics and Computing (CEMC): a math outreach organization at the University of Waterloo, offering competitions and math circles
- Problem of the Week from The Math Forum

- Take Math Classes Online
- AoPS Courses (low cost): excellent online math courses for high-school students, with homework and feedback from instructors
- Stanford Online Courses (requires per-class tuition): university courses for pre-college students, self-paced and with instructor support
- Coursera (free to audit, low-cost with financial aid available for enrollment): large open online courses, scheduled for 5-14 week sessions
- The Online Courses Directory (free): a collection of online college courses from major universities (such as MIT), study at your own pace

- Interesting Topics in Mathematics
- Frequently asked questions in math (a '90s throwback, but still a great collection!)
- Famous Curves
- Fractal Dimension - How to compute?
- Symmetry and the Shape of Space
- Common Errors in Undergraduate Mathematics
- The Riemann Hypothesis
- Cut-the-Knot

- Interactive Web Utilities
- Wolfram Alpha - a computational knowledge engine, free and very powerful
- Euclid's ELEMENTS
- Non-Euclidean Geometry
- Gallery of Interactive Geometry

- Mathematics in History and Culture
- Proofs and Proof Techniques
- How To Write Proofs
- The Pigeonhole Principle (and some fun applications)

- Collaborative Spaces by and for Research Mathematicians

(Watch research unfold!)- Math Overflow: for mathematicians to ask and answer research-level math questions
- PolyMath : a blog and wiki for "massively collaborative mathematical research projects"
- The Open Problem Garden: a collection of unsolved problems in mathematics