And time your presentation, reading slowly! Some conferences, like Organization of American Historians, provide you with exact word counts for a 15-minute and 20-minute presentation and you would do well to adhere to these guidelines. And others, including OAH and the Berkshire Conference on the History of Women, Genders and Sexualities, require you to submit your papers to the person selected as "Commentator" no less than two weeks before the conference, so don't be that person still writing your paper on the airplane en route!
Read your paper aloud several times to catch (and change) awkward wordings. Time yourself to one minute less than the allotted time and edit as needed. Once you have it in final form, print it triple spaced in a large (size 14 or larger) font, bolded. Number your pages. Do not staple them. Put the pages in a folder, paperclipped. Remove the clip before presenting.
Send your paper to your discussant by the deadline set by the conference. If organizers have not set one, email the discussant and ask her/him. Most people would like it a few weeks in advance. That -- and not the conference -- is your deadline. Send *exactly* the version that you will be sharing with the audience. Asking another scholar to read two or three times the material you can share in the time allotted to you and to guess what to address in her/his comments is disrespectful.
Practice your presentation. Read it out loud (even if it is just to yourself). You'll catch a lot of mistakes that way, and it will help with your nervousness. Also, the more familiar you are with your presentation, the easier it will be to maintain a degree of eye contact with the audience.