Uploading your contact list to mailchimp is a big hang-up for many mailchimp users. That's a problem, since it's a pretty darn important step.
Here's the skinny: a little prep work will make this quite easy. I like to start by organizing my contacts in an excel spreadsheet.
At this point, you should think about what kind of segments you might want to use to split up your list and add columns accordingly. Segments you might consider include: location(zip code or major metropolitan area or even street address), interest(do they want to know about live events?).
In addition to whatever segments you want, you should always have two separate columns for first name and last name. This makes personalizing your emails with merge tags quite easy, so don't forget.
In the end, your spreadsheet might look something like this:
After that, log in to Mailchimp and hit the "Lists" tab. From there you can create a new list, or update an existing one. Using the additional info you added to the spreadsheet will help you maintain just one versatile list, which will save you a lot of hassle down the road.
Once you've got your list going, it's time to import. Note that email marketing best practices demands that the folks on your list have given you permission to send them email newsletters. No point in uploading them if they're just going to unsubscribe after the first campaign anyhow. Overzealous importing of cold email lists will get your account flagged, and potentially suspended.
On the page for your list, select "Import" on the top menu bar. You'll see a lot of options. For this method of import using your prepared spreadsheet, select "Copy/Paste from File" or "CSV"
The text box that shows up auto populates with examples of segments from your list. Don't worry about those, just paste your contacts from the spreadsheet like this:
UPDATE 12/19/13 - If your data doesn't line up like the picture, don't fret. Proceed to the next step. If the column-matching section is jacked up, click Cancel, then check for spaces and/or special characters, and run the copy and paste routine again.
Hit the "Import List" button.
Now for the fun part, assigning the data you just pasted in there a heading. The screen that comes up next looks like this:
Hit that "Done" button and you're good to go. The copy/paste method is good for uploading small batches at a time, the CSV option for larger imports. Importing contacts via the many integration options can be handy too, but can get a hairy fast, so if you get stuck, give us a call!