Learn Hardcore Turkish: Belgeleri taramak için tarayıcıyı bilgisayara bağladım. - I connected the scanner to the computer to scan the documents.

In Turkish, definite direct objects take the accusative suffix –ı/–i/–u/–ü. Since tarayıcı ends in a vowel, a buffer consonant –y– is inserted before the suffix to avoid two vowels in a row:
tarayıcı + y + ı → tarayıcıyı (“the scanner” as a definite object).

What does taramak için mean, and how is it formed?

–mek/–mak için attaches to the verb infinitive to express purpose (“in order to …” or “to …”). Here:
tarama-k (to scan) + için → taramak için (“in order to scan” / “to scan”).

Why does bilgisayara end with –a?

–a/–e is the dative case marker (“to/into”). The word bilgisayar (“computer”) ends with a consonant and has a back vowel a, so we add –a:
bilgisayar + a → bilgisayara (“to the computer”).

Why isn’t the pronoun ben (“I”) explicitly in the sentence?

Turkish finite verbs include personal endings. In bağladım, –dım marks past tense + 1st person singular. The subject ben is understood, so it’s usually dropped.

How is the noun tarayıcı (“scanner”) derived from the verb taramak (“to scan”)?

By adding the agent/instrument suffix –cı/–ci/–cu/–cü to the verb stem (with a buffer –y– if the stem ends in a vowel):
tarama-k → tarama + y + cı → tarayıcı (“scanner”).

Could you omit the accusative –ı on tarayıcı in this sentence?

Omitting the accusative (tarayıcı) would make it indefinite (“a scanner”), but in this context you’re referring to a specific scanner you own or have in mind. Turkish marks definite direct objects with the accusative, so you need tarayıcıyı.

Why does the purpose clause Belgeleri taramak için come before the main clause rather than after?

In Turkish, subordinate clauses (like purpose clauses with –mek için) generally precede the main clause, and the verb of the main clause stays at or near the end. So you place Belgeleri taramak için before tarayıcıyı bilgisayara bağladım.