IRC is easy to use as >>10899397
kindly pointed out, but you can actually get by without it most of the time.
Not many groups release EXCLUSIVELY on IRC. They will often have Rapidshare or other filesharing options, Torrents, or DDLs available.
For groups that release exclusively on IRC, all is not lost either, since there are various sites like Mangatraders which should acquire the file within a day or so and have it for DDL (albeit at quite vastly fluctuating speeds).
I heartily recommend IRC though, it really can't be beat once you get the hang of things.