For optimum sound quality, do not use onboard line in ports. You need an external ADC (Analog to Digital Converter). This makes or breaks digitizing LPs. Tascam makes good ones. I cannot stress how important this device is for this procedure. Coming from personal experience, it makes a HUGE difference. There are also some onboard soundcards that do a decent job with this, but I'd go external.
Also, Audacity is simple and easy but it has a huge flaw. It is tricky to get it to record high resolution sources. For example, lets say you are trying to capture your analog source at a 24bit 192khz digital rate, which for initial digitizing is what it should be at. Audacity for some setups will not truly capture the 24 bit 192khz source. It will create the overhead in your file and metadata to appear as if you are capturing it at that rate, but the audio in fact is not reaching the higher resolution. There are workarounds to this, but I personally would use something different when it comes to hi-res audio.
Wavlab is good, Adobe Audition is better.
Hope he has a good record cleaning setup as well. This is very important otherwise get ready for some ticks and other crap.