So!  You're just starting out collecting portable typewriters.  Perhaps you already have several; maybe you just have one.  No matter; the desire is all that's necessary, coupled with a few tools.  Here is your complete "crash course" in HOW to collect.  Between this article, and my site "Will's Typewriter Annex" which helps you maintain and supply your machines, you're all set. 
Here is our first lesson. This picture shows the lineup of Smith-Corona portables which were available in the year 1958.  This is just an arbitrary selection; the important thing to remember here is that typewriter manufacturers were kind of like car manufacturers.  Many of them had whole lineups of models, with varying numbers of options and thus varying prices, available at all times.

You will note that there is one machine, the Skyriter, shown here with its case, that is much different from the others.  It is in a whole different size class, and does not compete with the larger machines.  It's targeted at different end users.  Likewise, the machine with the cord is obviously electric, and although it looks like the other big machines here, it's really different (by necessity) inside -- and is MUCH more expensive.  The other three are basically the same, except for options.
What do I mean by options?  One really big one is a tabulator, which is used to rapidly move the carriage to selected spots for typing in columns.  Some have no tabulator, while others have a tabulator with stops that you have to manually move just like you would move the margin sets.  The "top end" option is a key-set tabulator, where you just move the carriage to a given spot, hit "set," and the tab stop is set there.  You can clear it, usually, with another key.  In the line you see here, the Clipper had no tabulator at all, the Sterling had manually set tab stops, and the Silent-Super had a key-set tabulator.  Really a complete line of machines.
Now, on the other hand, there were manufacturers that offered portables, but which only offered ONE model at a time.  This Oliver Courier is an example of that phenomenon.  One model at a time, with no optional equipment.  "It is what it is," and that's it.  This happened only rarely -- usually, makers had at least two models in order to be able to compete.  Some of them had models in different size ranges simultaneously, while others did not.  Some models ran for years and overlapped later ones, while others were dropped immediately when another came out.  This is part of the fun of collecting -- learning just what the history for each brand name was, and how it all fits together.
Just to drive home the differences in competitive classes by size, we see above the Gossen Tippa, and at right an Alpina-derived Avona.  The Tippa is actually smaller than the picture makes it appear; the Avona is bigger than the picture makes it appear.  Note the flatness of the Tippa, and the massiveness of the Avona.  This large competitive range meant that, usually, only the biggest makers would attempt to simultaneously build such wholly different machines (often in addition to standard office machines.)
Below are some links to pages on my site.  They're recommended reading for new collectors.  It will help you greatly if you read and re-read them, not to simply learn the names and models, but to understand how product lines evolved and changed over time, and in relation to each other.
Classification of typewriters by age.
Relabeling and how it works.
Look inside a typewriter.
There are articles on my site about Royal, about Corona / Smith-Corona, about Remington and about Underwood portables.  These are the common fare for beginning collectors, in the United States; for our exercise in "Portables 101" they're required reading!  Suggested is the article on Travelling Typewriters.
Visit all of the links above, and then use this button to continue to the next article.