First, the 1099 is a setting that can be found in the vendors menu, or under the vendor center. This setting can apply to either a new vendor you are setting up, or a current vendor that has already been set up. Either find the vendor and right click on their name to select edit vendor, or select new vendor to create your vendor. In the vendor set up menu, the "tax settings" tab determines if the vendor will be eligible for 1099. You will need to select the check box for "Vendor eligible for 1099" and enter their social security number, then hit OK.
Once this is set, QuickBooks will track the payments made to that specific vendor, and as you are preparing you 1099 forms to send to your vendors, if that vendor has hit the threshold required by the IRS, they will populate in your 1099 report you will run. The 1099 wizard can be found under the file menu, "print forms" and then select "1099's". QuickBooks should automatically select the vendors that you have set to be 1099 eligible and prefill most of the information that is needed for the wizard to perform.
You will need to map the money that you have paid to vendors by selecting the accounts "box" to which type of payments were paid. Typically with vendors almost always the account that will be selected will be "non-employee compensation"