I explained some of my deductions to the IRS on a sheet of paper, medical, contributions, and sales tax, do you think that is OK to do ahead of time thank you

Did they ask you to explain? Normally no, you merely fill the forms out, as proper, and that is it, unless they ask for future explanation.

If you're filing a paper return (not electronic) then sure, you can always add detail if you like. However, as Fr_Chuck says it's not necessary - if the IRS has a question they will come back and ask about it. But in general they are unlikely to do so unless your deductions are highly unusual. I would advise that you keep the document with your own paper copy of your return, so that if the IRS comes back to you in a year or two for an explanation you'll have it readily available. Also be sure to keep your receipts as proof of these expenditures.