As a new user of LimeWire, could someone help me?
How can I know wich softwares are for Mac before downloading.

Programs for Mac are usually StuffIt files with the suffix .sit. Avoid anything with the suffix .exe and .zip.

My strategy is thus: I open limewire, click the "programs" button for software search, and enter "mac" under file name. Some software is exclusively for mac and with others there is a version for each platform. .dmg files are disk image files and can usually be used. Use stuffit expander to open them and try mounting the image with Toast or with a disk utility. Suggestion; get Toast Titanium 5.xx from the network. You will need a serial number and sometimes, folks don't include them in their shared file. There are lots of serials out there, just look for the specific title's software and "key" or "sn." By CAREFUL with Adobe crap, they are nasty and have been very sneaky about adding a "secret" web engine that uploads your IP address to their spies. This can be prevented by compressing certain files in the apps preferences folder. You mustn't be connected to the internet when you install things like Illustrator, Photoshop, etc. If you are on a server or cable internet, pull the ethernet plug out of the back of your mac before you install. If you need details on this, email me and I'll send you step-by-step instructions.

Good Luck,

Jeff