I am Canadian, would like to visit China (Beijing) and stay for 4-5 days

You just have to apply for a China tourist visa for your 4-5 days visit in Beijing. The documents you need for the visa application are listed as below:
1. Your passport with enough blank visa pages, valid for at least another 6 months
2. A fully completed Visa Application Form signed by yourself
3. One recent 2×2(in.)-sized color passport photo, white in background

It seems that the Hotels reservation is not necessary, but you'd better prepare it and the air ticket to HK well. Having is rather better than not having.