The tourist (L) and transit (G) visas are the only ones that you can apply for without assistance from a business, government or academic institution. 

Most visitors to China will only require a tourist L which will allow them to travel freely in most parts of China as tourists. If your situation is not described by one of the other visa types, then this should be the one you need.  

If you are travelling in an organised tour group you might not have an individual visa in your passport.  Instead, the tour group will be issued with a group L. The invitation letter issued by the travel agency is required. In such situations you will supply your details to the travel agency before you travel and then you have no further concerns. If you are travelling to Hainan province in an organised group you might also find that no visa is required.

Requirements 
1. Applicant' passport with at least 6 months remaining validity and available blank pages. 
2. One truly completed Visa Application Form. Please fill in every column of the application form, using "N/A" if not applicable. If the application form is not filled out truly, completely and legibly, this can cause a delay in processing or refusal of the application.  
3. A recent passport-size color photo with white background stuck on the application form.
4. Proof of legal stay or resdence status (applicable to those not applying in their country of citizenship)
5. Documents showing the itinerary including round trip air ticket booking record and proof of hotel reservation, etc. Or,
Invitation letter issued by a relevant entity or individual in China, with following information:
  a. Information on the applicant (full name, gender, date of birth, etc.) 
  b. Information on the planned visit (arrival and departure dates, place(s) of visit, etc.) 
  c. Information on the inviting entity or individual (name, contact number, address, official stamp, signature of the legal representative of the entity or the inviting individual) 

For tourism, applicants may also need provide the below required documents on a case-by-case basis: 

Tibet Travel Permit (click to enlarge)

6. Certification letter from the working unit of the applicant (with details as follows: name and contact number of the working unit, the applicant's income statement), or original copy of recent 6-month bank statement of the applicant. 
7. If it is not the first time for the applicants to apply for Chinese tourist L for tourist purpose, a personal statement is required if necessary, with the following information: reasons for revisit, the places the applicant plans to visit this time and places he/she visited before.
8. For applicants who will travel into Tibet, they must obtain a Tibet Travel Permit. This can either be obtained by joining a group or by obtaining the permit from Tourism Bureau of Tibet Autonomous Region (Tel +86 891 6834313 or Fax +86 891 6834632).

How to Apply
You can come to the Chinese Embassies, Consulates and other Chinese diplomatic missions to submit application in person; if you can't come personally, you can entrust someone else, a travel agency or a visa agency to act on your behalf. No appointment is required. Applications by mailing are not acceptable and will be refused at most of Chinese embassies or consulates.

Processing Time
It regularly takes 4 working days for processing. For express service, additional fees of US$ 20 will be charged for second or third working day releasing. For rush service, additional fees of US$30 will be charged for the same working day releasing.

Visa Fees
The fees vary enormously depending on your nationality and number of entries. However, according to the Visa Fee Abolition Agreement, the nationals of following seven countries are free of the fees, but they need pay for the express service, rush service or mail service: Pakistan, Maldives, Bulgaria, Bosnia-Herzegovina, Slovakia and Micronesia. Application by mail is not accepted by most Chinese embassies or consulates, but in countries with the Chinese Visa Application Service Centre (CVASC), applicants may be able to apply by post, or submit applications based on online appointment via CVASC's website.