I'd consider a two pronged approach. First set up a magma driven workshop by the pool and start to produce 20 magma safe screws, pipes and blocks (blocks are easy: just make rock blocks out of a magma safe stone (check the wiki for those). Screws and pipes can be produced from green glass (any glass actually, but why use trickier to produce ones), iron, steel (why waste steel if you've got iron, though), candy, and nether-cap. Check the wiki on how to produce a pump stack. I'd power the stack with water wheels, because:
- Only some embarks have wind (latitude dependent)
- Wind mills produce 0/20/40 power depending on embark latitude, and are vulnerable to building destroyers unless you pour a fair bit of work into securing them (especially the power train).
- Water wheels produce 50 power. If you've got an aquifer you can do that completely safely.
If the only thing you're going to use the magma for is power a new workshop a bit higher up (as opposed to e.g. spreading death and mayhem on your enemies, or obsidianizing cavern lake entrances) you may consider pumping each level of the stack manually, or, easier, fill a magma safe mine cart (the materials above EXCEPT nether-cap) with magma and manually haul it up to a track stop by a channeled out singe tile in your workshop floor, have the track stop dump the contents, collect a second dose (workshops require 4/7 magma), build your shop (after removing the track stop, of course), and repeat for any other workshops. You can also use the method to create a magma dumping pit for stripped enemies (see mass pitting on the wiki).
I'd seriously consider the pump stack because it's a great opportunity to get an understanding of a new aspect of DF.
You don't need a huge pool of magma for your workshops a single tile of 4/7 depth is enough for each shop. Thus, I'd dig a tunnel above which I'll place the shops in a row (you can make a bend if you like, to get the shops where you like them of course). It doesn't hurt if the tunnel is longer than needed, but it's no great calamity if it's too short, is it's possible to extend it.