Hmm. I think the programme memory allocation stuff is beyond me at the moment but I do want to continue with assembly for now.
How do you organise variables in memory?
It would be a little easier, if you told us which family of chips you plan to use. Although the method in Assembly is basically the same for most chips, there are differences. If you are using an enhanced mid-range chip, then there are more options as I and NorthGuy have pointed out.
First, I try to minimize the number of variables I use. Most of my stuff has a 'temp' and a 'count' register; although, I may not use both in a final version of the code. You could call them whatever, e.g., temp0, temp1, ... Some people prefer acc or accum, etc.
For such variables, I use Common RAM. It starts at 0x70 and goes to 0x7F. It is accessible from any bank, but of course can hold only 16 bytes.
For variables that will only be accessed when in bank 0, I use the space beginning at 0x20 and going to 0x6F. It is called General Purpose RAM. Most important, it is banked. That is, each bank has its own section. Go to Table 3-3 (usually)called "Memory Map."
If you need a really large area of contiguous RAM, then you can use what is called "Linear Memory" (also described by NorthGuy). That uses indirect accessing (i.e., FSRn and INDFn) and acts as if all of GP RAM was one space. Depending on the chip, that can give access to hundreds of contiguous bytes.
In actual practice, I use mainly GP RAM at 0x20..0x6F (Bank 0) and Common RAM at 0x70..0x7F almost exclusively. If I need a large space for variables that change frequently, like for a buffer, I use Linear Memory. I tend to start that buffer at 0x80 (actually accessed indirectly at 0x2080) to preserve the lowest bank of GP RAM. Banking is really a non-issue for me.
EDIT: BTW, if you like a lot of different register names ("aliases"). You use as many as you want. The same register location can have several aliases as can the individual bits in different registers. Just look at the .inc file for your chip and you will an extreme example of that.