Barbara Hettle and Lisa Davis are 2 former homeschoolers that I know do consulting. However, by far, most homeschoolers do not use consultants (me included) and apply to colleges without professional guidance. You can find all the answers you need on the internet.
What homeschoolers should do is apply with as much information provided as possible. In addition to a transcript, they should have course descriptions of the courses completed, materials used, and how grades were derived; they should have a school profile that describes the methodology and philosophy of the homeschool’s operation; their primary teacher should write a counselor letter describing the student.
Whether or not you should have oodles of outside grades, that is debatable. My kids have all approached high school differently which is why we homeschool–customized educations. I have had kids DE and graduate with numerous 200/300 level courses. I have had a dd who did not want to be confined to a typical outside teacher’s classroom coursework, and we designed all of her courses with the exception of 1 that she took through an outside teacher and 1 DE course she took spring of sr yr (after all apps were completed and acceptances heard before she had a grade.) BUT, the courses she was taking were obviously at a very high level (she took a course on the psychoanalysis/cultural themes of fairy tales and folk lore, read Hugo in French, studied French history in French, etc.) Her test scores reflected her abilities and her ECs were stellar. Her outside teacher affirmed her academic strength.
My current high schooler is not as strong of a student as some of her siblings. She won’t be applying to competitive schools or for competitive scholarships. Her application will be far more basic. She won’t need much more than transcript, course descriptions, and test scores.
First, know your state’s/school district’s homeschool laws. Make sure you comply with the requirements. I homeschooled my son and he is now a freshman at a small Catholic college. He supplemented his instruction with online classes (foreign language and AP maths and science). He had lots of church involvement for extracurriculars. He took the SAT twice and ended up with a 1500. He took the AP Calculus exam. Hope this helps! Good luck!
Spend some time looking around this homeschool college forum and/or asking questions there. They are a SUPER helpful and knowledgeable bunch who have BTDT or are in the midst of it.
My oldest is applying to school as a homeschooler this year. I fully expect him NOT to get a full scholarship anywhere and he has a 99% ACT score.
To apply to college as a homeschooler hoping for merit aid you will want
extensive documentation of your homeschool process. You will need a school profile document and a LONG transcript with curriculum, book lists, teacher names, resource names, credit information and graduation requirements. I hope you have a parent willing to put in a lot of hours on this
An ACT and/or SAT score preferably at or above the 75% of schools you're look at
Another chunk of verifying data is good. This can come in the form of SAT-2 tests, AP tests, a dual enroll transcript, outside class grades that are well documented. You will probably want at least 3 or more outside classes/tests. Note that some schools list particular requirements for homeschoolers (though sometimes they can flex on these if you have good other documentation).
Some indication of what you did with your extra time as a homeschooler and some collaboration and leadership skills.
There are actually some disadvantages to having skipped a grade. Especially as a homeschooler when you can learn at your own pace regardless. The most competitive applicants to schools are wildly gifted and have had that extra year to develop their extracurriculars and maturity level.