This is the final result of this tutorial:
Let's start by deleting the default cube (X) and adding a circle (Shift A - Mesh - Circle), then on the left, check the box next to 'Fill'. Go into top orthographic view (Numpad 7 - 5), and rotate the circle 90 degrees along the X axis (R - X - 90). Enter Edit Mode (Tab), extrude the circle along the Y axis (E - Y - 20) and scale it down (S - 0.75).
Tab back into Object Mode, and select 'Smooth' on the panel to the left. Not tab back into Edit Mode, select everything (Press A twice), and press Ctrl N to recalculate the normals. This will get rid of the strange lines on the mesh (which are only really noticeable in Object Mode).
For the area around the lens, I'm going to create it so that it's disconnected from the handle, but it appears to be attached. Make sure you're in Edit Mode, and add a circle (Shift A - Circle). Scale this circle up (S - 9) and move it along the Y axis so it's at the top of the handle (G - Y - 28).
Go into front view (Numpad 1) and move the circle up along the Z axis (G - Z - 1), then extrude it down (E - Z - -2). Select all of the vertices linked to this circle (Ctrl L), and go back to top view (Numpad 7). Now extrude this in (E - S - Shift Z - 0.9).
Now press Ctrl L again to select all of the vertices linked (or connected) to the ones you have selected, and on the left click on the 'Smooth' option in the 'Shading' tab. Now we'll have to recalculate the normals again, so with the area around the lens still selected, press Ctrl N. Now click on the 'Modifiers' button on the right, and select 'Subdivision Surface' from the drop down menu.
Set the View levels to 2, and enable 'Optimal Display'. You'll notice that the magnifying glass looks too rounded now, so we need to add more edge loops to sharpen the edges a little more. Start by tabbing back into Edit Mode, and adding an Edge Loop on the handle (it should first display as a purple line; make sure that this line is horizontal and not vertical). Do this by pressing Ctrl R, clicking, and moving the mouse to where you want the edge loop to go. To sharpen the top of the handle, move the edge loop towards the top, but not all the way to the top.
This is the example that I've used; you can also create vertical edge loops, but that wouldn't be a good idea for the handle. I'm not going to go through every edge loop; just remember to add an edge loop where you want an area to be sharper.
We'll be making the lens a separate object, so tab into Object Mode, and add a circle (You should now how to do this by now). Select 'Fill' on the panel to the left, and scale the circle up (S - 8.5). Now press G and move the circle so that it fits inside the lens area.
Now tab into Edit Mode, deselect everything (A), and select the middle vertex (Right Click). Go into front view, and move the vertex up to the height you want it to be (G - Z). Tab back into Object Mode, and select the 'Smooth' option again, and recalculate the normals (Ctrl N)(Be sure to tab back into Edit Mode before doing this). It's up to you if you want to put in more detail work, but I won't go into this for time's sake.
This concludes part 1 of the magnifying glass tutorial! Congratulations if you completed it, and I hope you finish the whole series once I've released them all. Again, sorry for the long wait, and if you have any questions, comments, or problems, post them in the comments below. Thanks for reading!