Lots of different ways to go about it depending on the model but generally you use sheets of balsa of various widths and lengths to fit the area to be covered.

Trim the sheet to generally fit an area of the fuse

Use water or water w/ammonia to wet the sheet and allow it to bend around the area to be sheeted.

Get the bend correct and final trim the sheet to fit PERFECTLY
When the fit is correct, glue it in place

You will need to balance the size of the sheets to minimize seems but avoid cracking the balsa with too much of a bend.

The grain of the balsa will run length wise to the fuse.

You will need to plan it out so that the sheet seams align over spar or other solid component of the frame.

You may need to add additional support for the seams to your frame.

Glue selection needs to be considered also. If you can reach the area and hold it in place, you can wick thin CA in. If not, you will need to use thick CA or aliphatic to allow ample alignment time.

If you use the slower glues, you will need to have a way to hold the sheets in place until the glue drys.

If you are overlapping one area, you can use chaulk on the lower surface then put the top sheet in place and rub where the sheets overlap. This will give you a mark on the underside you can use to cut your sheet.

Ok, thats all I can think of right now. You're kit really should have detailed instructions. Another option would be to go to the Top Flite web site and download a manual to one of their warbirds and adapt their technique to your model.