You've given it a lot of consideration, and the time seems right. You and your child both feel that she should look into beginning college coursework. Whether she is eight or sixteen, there are certain things that should be considered. A first college venture should be carefully planned to provide a positive experience. Now is not the time to register for a full schedule of challenging classes in areas that your child has not previously explored. A single course in a topic your daughter is familiar with and excited about is often the best way to begin. If history is her passion, then steer her in that direction rather than toward biology or French, unless she is equally excited by those topics. Let her taste success with something personally meaningful and exciting before she puts her nose to the grindstone for a course that is less interesting to her. Once a first course has been successfully completed, then you can look into additional courses or perhaps full matriculation.
What if you are not sure if she can handle college level learning yet? You can expose your child to college material through textbooks, which can often be purchased cheaply if you don't mind foregoing the latest edition. Used sources abound online, and some people are eager to get rid of old texts that take up too much shelf space. This a great way for the student to see what college material looks like in a particular subject. Encourage your daughter to read a chapter or two, and she might decide to work through the whole book.
Another fantastic resource is open courseware. Open courseware is offered online and completely free, though you may need to purchase or borrow required books. There are literally thousands of free online courses available, many of them offered by top notch universities. MIT's Open Courseware features a catalog of 1800 different courses. Sample courses include The Art of Counting, How to Stage a Revolution, and Introduction to Fiction. No matter what your gifted student is into, there's sure to be something here of interest. The Johns Hopkins Bloomberg School of Public Health has some excellent offerings, including Adolescent Health, Population Science, and Genetics. Carnegie Mellon University calls their program the “Open Learning Initiative”, and here a student may find Statistics, Chemistry, and French, among many others. The University of Washington has free courses such as Gulliver's Travels, Greek Mythology, and World War II. Do a google search for open courseware or free online courses and you are sure to get plenty of hits. This is a great way to get exposure to college courses with no risk whatsoever.
If your son is ready for serious college work, he can choose to audit or take a course for credit. He may opt for online enrollment or a live classroom experience. Remember that it is best to start with an area of interest, and be confident that he has the skills to keep up with writing, discussion, and other requirements. A young first time student is making an impression on the professor and other students, and you want that impression to be a positive one. It's also critical for the student himself to feel good about the early college experience. If parents assist their child with preparation, everyone should walk away feeling good.