Potato bed question

Hi, I am just digging a new bed ready for my potatos.  I have first and second earlies and main crops.   I am hoping to plant the first earlies at the middle/end of march.  My question is can I dig in some well rotted manure now?  Or will this be bad for them?  If I can't is there anything else I can do in the next week to improve the soil.  It is a new piece of ground in my garden that was previously weed and grass so I am clearing it now, halfway through    I have a bit of garden compost so could add that.  But wanted to know what was the best thing to do.
Juliet

Get as much in as you can!

Thanks for all your replies - will get digging!