My first amiga 1200

[amiman99]

Great!
When it gets released, you need to get this accelerator from AmigaKit http://amigakit.leamancomputing.com/catalog/product_info.php?products_id=1100
ACA 1220 128MB Accelerator, not much speed gain, but it comes with whooping 128MB RAM, great for WHDLOAD and more, and is under $100.
And yes, you need IDE 2 CF adapter for your HD, and PCMCIA-CF adapter for file transfers from PC to Amiga.

[amiman99]

WinRAR is a compression format like ZIP, so you need a decompressor like 7-ZIP. 7-ZIP handles many formats including RAR, ZIP and even LHA.
To transfer files between PC and your A1200, first copy the files from your USB HD to PC.
You also need CF card reader on you PC. IF you have one copy the Amiga files from USB HD to CF card.
I don't know if you have CF drivers installed on your Amiga's HD, if you do, then turn off you A1200, insert PCMCIA card with CF card to the slot. Turn it on, new disk should show up on desktop.
sometimes you need to select "Show All Files" to see the contents.
If you dont have CF drivers already installed, you need to get them from Aminet http://aminet.net/package/driver/media/cfd and FAT95 http://aminet.net/package/disk/misc/fat95
The FAT95, just copy the file from "L" folder to you System:L
The CFD, copy the DEVS folder contents to System:DEVS. If you want the CF0: to start on bootup, move the CF0 file to DEVS/DOSDrivers folder.

I dont know if this is too much info for you, but here you go