I have a question about particles in the two following sentences.

京都というレストランがどこにある　(か/のを) 教えてくれませんか。

Are か and のを exchangeable in sentences like this one?

お客様に部屋を案内しました。

Is this sentence acceptable? The verb 案内する is somewhat confusing to me...

The particle choices are か, のか and のかを for the first sentence. Note that のを is not a possible choice and also note that か will always be needed. 　か is used twice here because you are, in effect, asking two separate questions.
1. Where is the restaurant named Kyoto?
2. Could you tell me?

The second sentence is correct only if you know what it means. It means "I showed the guest around the room." When a native speaker sees/hears this sentence, s/he will imagine that you are talking about an unusually huge room.

The verb 案内する is actually fairly difficult for the learner because it can take both persons and objects as a direct object.
1. You show someone around a place.
2. You show a place to someone or simply take someone to that place.

お客様に部屋を案内しました。 = the huge room story above
お客様を部屋に案内しました。 = "I showed my guest to the room"

I'm sure he meant to say けんいち.

Thanks for the answer! I appreciate it.

:) Thx for the help I see I messed up on little things, I copied the first sentence wrong I forgot to put the を when I transferred it over to my phone, I'm going to start double checking my work. masaegu was right lol I meant けんいち.

 I forgot to add this last sentence. I just wanted to see, if  I could say lee friend will come to the cafe today.
りーさんのともだちはきょうきっさてんにきます。

That is perfect. To be anal, though, りー should be written as リー since it's a foreign name.

Thx for the quick reply. No problem, I'm glad u told me it helps me out in the long run.

 Hey it's me again my last question for the night I promise... I was wondering this sentence from Genki textbook has the the に particle after Saturday can If put lee in front of will it be correct still. I second guess my self to much :)

どようびにきっさてんにいきます。

リーさんはどようびにきっさてんにいきます。

Long time no see JF! No questions for now, I just wanted to bop by and say thanks to Supperman and Masaegu for the help. Also, masaegu, I saw your message to me on Lang-8 this morning. I'm so sorry for not responding sooner. I don't use Lang-8 much. And since JF has been down I haven't been on my computer here lately. Moreover, my younger siblings have decided they like my laptop better than their old computer so I can barely get on the dang thing! ;) Glad to see JF is back, I was gettin' worried :D

Both are good sentences.

I think you are doing yourself a lot of good by trying to form different sentences. Adding, subtracting and switching words should help you feel more comfortable with the language as it lets you play with it.