ok, just for practice...
first off, maybe you would like to make your UI like you see mine here... it takes some getting used to in how they don't act like standard windows in certain ways, but... once ya get things the way you like em they are really helpfull in the selecting the other side as well different perspective viewing...
go up into "window" and choose new geometry window, and again, and once more... you will notice they each come with menus, just stackem like you see with mine... might take a while to figure if one goes behind the other, but... none the less, once you have em stacked to which ever arrangment you like then... right click on the green menu bar of your large main window and choose "fit" "horizontal"... ( do not hit vertical, or be prepared to fudge around way too much... )
There now you have multi viewports however small, they come in handy...
Now then ...
Bridging
Pop a cube in your work space... ( now go into your small view ports and position your views re middle click in each viewport and dolly the cube so as one has the top, one shows the opposite side, and one shows the front...
now go into the main window and...
select on any face and extrude out... (keep in mind axis)
deselect all, then select one of the center edges and hit "L" to loop middle lines/edges...
right click and choose "loop cut"
now right click and choose move, along same axis as the face you had originally selected... and the two sides should seperate horizontaly apart from each other...
deselect, then select the two inside faces ( one by selecting in view in the large work window and the other side through the smaller window showing such... practice this, it really sppeds things up in these early stages where the models are still fairly small)...... right click and choose "bridge" Bridge will only bridge the gap between two poly faces, so... if you have a center area which has a long row of inside faces, select said faces and hit your backspace to "dissolve" thus now you are left with a ngon ( has more than four sides) but no the less it is but one poly, thus your are able to select the two dissolved inside areas and "bridge" them.
any problems give me a hollar...