they should be on your 1099-DIV in Box 12 and maybe 13 for AMT. Just enter the 1099-DIV as it comes and the Box 12 should reflect as exempt for Fed tax.
For State calculations if applicable, TT should prompt you to provide the muni amounts by state, but you should only need 2 entries, one for your home state vs. the rest (select "Multiple States"). The mutual fund should have a Supplemental Tax Info sheet which has the % breakdown by state to do this calculation, or it could be at the back of your statement if a firm like Vanguard.
I use desktop and manually input my 1099s, but same general principles should apply if doing import or online.