Mary, they've been in storage so let's assume they have been kept in a cool place, have not been watered, and kept out of light.
Now the sun is returning, soon it will be April and high time stored plants can come ouf dormancy and given fresh potting soil, a clean pot, something to keep the soil away from the drainage holes, the plant cut back to encourage new foliage and water to enable it to take up nutrition.
The amount of cut-back is up to you but usually 4" is a good size to take it back to. Clean away all old stems, broken or damaged, any old leaves or flowers hanging on.
Use sharp scissors or pruners so that you see good green.

Soaking the roots will be done after you plant it because you will water the plant until drainage is seen below.
Soaking the roots might be considered if you feel they wont get the required water when you water the plant but if you give it frsh soil, a thorough watering after planting, there should be no concern for the roots getting their fill.

The water that accumulates in the saucer below will be left for about 10 minutes to allow full drainge....then dumped so that it cannot be re-sucked up around the roots which got rid of it.
Then given the best sun you can give it...south or west or east is a good esposure and in about 10 days you should begin to see new growth and advancing foliage each day for about a month when the foliage will be quite full.
When first watered, no more water unttil it begins to foliate, then only as the plant needs it. Every time you water, water to drainage and dump the excess.
Poke your finger down to test whether dampness is there...if so, let it go another 2 - 3 - 4 days, then test again. Do not overwater...the plant can only use a little at this time....its the sun that determines how fast the plant grows and its easy to water too much thinking the plant needs it. The finger test is a reliable way to determine that.

Each or every other day, turn the plant 1/4 turn thus ensuring all parts of the plant is receiving adequate sun.

Don't be concerned if the flowring doesn't come before setting it outside--it will come in its time.
When temperatures outside allow it, put it out during daylight hours, back indoors at night, back outside -- indoors...each day giving longer periods and acclimatizing it when it will go out and stay out.

Geraniums expand greatly their roots and can be given containers that suit their roots.

Goren, Thanks you so much for the quick reply and information! I was hoping for an answer this morning as I wanted to pot the geraniumns up. I will follow your direction and I am sure I will have a beautiful show later this summer. Thanks again!

why are the leaves turning white on the ones I stored overwinter.
why are the buds dry instead of blooming on the ones I just bought?